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Query: UNIPROT:P08758 (
annexin V
)
9,383
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Programmed cell death (apoptosis) can be found in normal thyroid tissue and in various diseases affecting the thyroid gland. The Fas/Fas ligand (FasL) system is involved in the induction of apoptosis in human thyrocytes. Cross-linking the Fas receptor with its own ligand or with an antibody capable of oligomerizing with the receptor induces programmed cell death. We investigated the role of Fas-induced apoptosis in primary human thyrocytes in vitro. Cell cultures of normal human thyrocytes were prepared from specimens obtained during surgery for uninodular goiter. Apoptosis was induced by incubation of the cells with a monoclonal IgM anti-Fas antibody. The presence of apoptosis was determined by FACS analysis of FITC-labelled
annexin V
binding combined with dye exclusion of propidium
iodide
. We found a significant rate of Fas-induced apoptosis in normal thyrocytes after activation with a monoclonal anti-Fas antibody. TSH was able to inhibit Fas-mediated apoptosis in a dose-dependent manner. This effect was more pronounced when thyrocytes were incubated in the presence of interferon-gamma. Low concentrations of
iodine
were able to inhibit apoptosis, while high concentrations of
iodine
increased the rate of Fas-induced apoptosis. Our results show that Fas-mediated apoptosis is inducible in normal human thyrocytes in vitro and is influenced by TSH and
iodine
. The Fas/FasL system may play an important role in the regulation of cell number within the thyroid gland, and may be involved in the processes leading to goiter in
iodine
deficiency.
...
PMID:Fas-Mediated apoptosis is inhibited by TSH and iodine in moderate concentrations in primary human thyrocytes in vitro. 1043 22
Conflicting results have been reported regarding the effect of TNF-alpha on the growth of human primitive hemopoietic cells. In this study, we have examined the effect of TNF-alpha on the proliferation of several CD34+/CD38+ (KG-1, TF-1) and CD34+/CD38- (KG-1a, TF-1a) myeloid leukemic progenitor cell lines. Our data show that TNF-alpha markedly inhibits the growth of these cells in both liquid and soft agar cultures. Addition of GM-CSF or IL-3 does not prevent TNF-alpha-induced growth inhibition. Flow cytometry analyses of propidium
iodide
-stained cells demonstrated cell death of all four cell lines, as judged by the presence of cells with hypodiploid DNA content after exposure of cells to TNF-alpha for 4 days.
Annexin V
assays detected apoptosis in TF-1, but not in TF-1a, KG-1, and KG-1a cells in terms of translocation of phosphatidylserine shortly after TNF-alpha treatment. Neutralizing anti-TNF receptor type I (TNFR-I; p55) Ab almost completely reversed TNF-alpha-induced growth inhibition in both liquid and soft agar cultures, whereas anti-TNFR-II (p75) Ab had only a marginal effect. TNF-alpha rapidly induced marked activation of nuclear transcription factor NF-kappa B in all 4 cell lines. The majority of this effect was abolished by the type I receptor Ab, whereas the type II receptor neutralizing Ab had no effect. Our data also show that TNF-alpha is incapable of inducing activation of the mitogen-activated protein kinase pathway in these leukemic cell lines.
...
PMID:TNF-alpha-induced growth suppression of CD34+ myeloid leukemic cell lines signals through TNF receptor type I and is associated with NF-kappa B activation. 1047 76
Previous studies suggest that the pineal gland may play a role in tumour growth inhibition. In this respect, melatonin, as the major hormone of this gland, has been extensively studied. However, there is growing evidence for the existence of other yet unknown pineal factors that may have tumour growth inhibiting properties. Here we describe the partial purification of a highly cytotoxic low molecular weight (<400 Da) hydrophilic fraction (designated F2M3R), starting from a porcine pineal extract (PE), via methanol precipitation followed by reverse-phase HPLC. F2M3R is cytotoxic for a highly apoptosis-resistant human erythroleukemia cell line (K562) at a concentration as low as 30 microg/ml. The viability of the cells was not influenced by an identical prepared porcine pituitary extract or by melatonin. PE induces apoptosis in K562 cells as indicated by three different criteria: morphology, in situ TUNEL assay and bi-parametric FACS analysis with
annexin V
and propidium
iodide
, but does not influence the viability of stimulated peripheral blood mononuclear cells. These observations warrant further purification and validation of the cytotoxicity in a panel of different human tumour and non-malignant cells.
...
PMID:A cytotoxic, apoptotic, low-molecular weight factor from pineal gland. 1049 72
Induction of apoptosis by daunorubicin (DNR) and idarubicin (IDA) was evaluated cytofluorometrically in CEM and CEM-MDR1+ leukemic cells exposed to drug concentrations similar to peak plasma levels obtainable in vivo (DNR 200-400 ng/ml, IDA 50-100 ng/ml, 30' incubation), and differentiating apoptosis from necrosis (FITC-annexin V+/propidium
iodide
- and + cells, respectively). Firstly, to set experimental conditions, apoptosis was evaluated in CEM cells at 3, 6, 12, 18, 24, 48, 72, and 96 hours from end of drug incubation, the maximal increase being noted at 24-48 hours. Net apoptosis rates were determined after subtraction of the spontaneous activity observed in untreated cells. The apoptotic effect from varying drug type and concentration was compared at 24 hours in CEM-MDR1+ cells, with and without co-incubation with MDR1 functional downregulator cyclosporin A (CSA) used at therapeutic concentration (1500 ng/ml). The results indicated that, at drug concentrations likely to be approached in vivo as a short-lasting peak level (IDA 100-200 ng/ml) with increased-dose IDA (> 12-15 mg/m2), pro-apoptotic effects by IDA+CSA in CEM-MDR1+ cells were significantly greater than by DNR+CSA, and corresponded to the levels observed with IDA 50 ng/ml without CSA in control CEM cells. This in vitro study demonstrates that it is possible to determine in the same sample cell fluorescence related to anthracyclines, apoptotic cells (FITC-
annexin V
positive), and necrotic cells (propidium
iodide
positive), and confirms that cytofluorimetric evaluation of apoptosis can reliably predict the effects of anthracycines in function of drug type, concentration and, in MDR1+ cells, concurrent MDR1 inhibition. Extension of this assay to the clinical ground may be warranted.
...
PMID:Apoptosis by anthracyclines at therapeutic concentrations in MDR1+ human leukemic cells. 1050 Aug 7
Interferon alpha (IFN-alpha) plays a prominent role in the therapy of a variety of diseases. The Fas/FasL system is crucial for the cytotoxic function and the peripheral elimination of activated T lymphocytes (ATC) by a mechanism referred to as activation-induced cell death (AICD). Recent studies suggest a link between IFN-alpha, the 2', 5'- oligoadenylate system and apoptosis. We therefore asked whether IFN-alpha is able to regulate the Fas/FasL pathway and thereby affects AICD. Peripheral blood mononuclear cells (PBMC), purified T cells and ATC of healthy volunteers were stimulated with various agents and the influence of IFN-alpha on Fas/FasL was assessed by mRNA and protein studies. The proportion of ATC undergoing AICD or anti-Fas-induced apoptosis was determined by FITC-
annexin V
staining and propidium
iodide
uptake. IFN-alpha upregulated mRNA expression of Fas and FasL in activated PBMC. Furthermore the concentration of the soluble form of FasL (sFasL) was increased in PBMC and T cells co-stimulated with IFN-alpha and various agents, whereas Fas surface expression was enhanced by IFN-alpha alone. IFN-alpha enhanced apoptosis induced by anti-Fas antibody and augmented AICD via the Fas/FasL pathway. IFN-alpha-regulated AICD may contribute to lymphopenia observed during IFN-alpha therapy. Our data further support that IFN-alpha is a multifunctional cytokine with profound effects on the immune cascades.
...
PMID:Interferon alpha augments activation-induced T cell death by upregulation of Fas (CD95/APO-1) and Fas ligand expression. 1052 11
Recovery from radiation-induced (RI) bone marrow aplasia depends on appropriate cytokine support. The early effects of exogenous cytokines at the hematopoietic stem and progenitor cell (HSPC) level following irradiation are still largely unknown, especially those of survival factors such as stem cell factor (SCF) and Flt-3 ligand (FL). This study was aimed at A) clarifying Fas/Fas-Ligand (Fas-L) implication in RI apoptosis of CD34+ cells and B) assessing the capacity of a combination of cytokines to mitigate RI apoptosis in HSPCs in vitro. We showed that most of in vitro gamma-irradiated CD34+ HSPCs incubated in a medium devoid of cytokines underwent progressive apoptosis-related changes from 6 h (i.e., decreased CD34 antigen expression,
Annexin V
binding); then Fas/Fas-L coexpression occurred from 10 h on. A strong DNA fragmentation, as assessed by TUNEL assay and propidium
iodide
staining, was observed at 24 h. Within a 2.5- to 6-Gy dose range, the RI apoptotic process finally led to 97% CD34+ cell death within 48 h with a complete loss of functionality. Unirradiated cells incubated in the same conditions displayed a significantly reduced apoptotic pattern. The early addition of a combination of SCF, FL, thrombopoietin, and interleukin 3 (4F) after cell irradiation prevented 15% (2.5 Gy) and 12% (4 Gy) of HSPCs, respectively, from RI apoptosis, whereas these cytokines used as single factors were inefficient. Furthermore, irradiated HSPCs (2.5 Gy) incubated with 4F in a serum-free culture system for seven days proliferated, giving rise to an increase in the number of total cells (x5.6-fold) and CD34+ cells (x4.2-fold) and to megakaryocytic and granulomonocytic precursors. These results show that the prevention of apoptosis in in vitro irradiated HSPCs depends on an early combination cytokine support. These data suggest that the early therapeutic administration of anti-apoptotic cytokines may be critical for preserving functional HSPCs from in vivo radiation damage.
...
PMID:The reduction of in vitro radiation-induced Fas-related apoptosis in CD34+ progenitor cells by SCF, FLT-3 ligand, TPO, and IL-3 in combination resulted in CD34+ cell proliferation and differentiation. 1052 62
Either inadequate or excessive apoptosis (programmed cell death) is associated with many diseases. A method to image apoptosis in vivo, rather than requiring histologic evaluation of tissue, could assist with therapeutic decision making in these disorders. Programmed cell death is associated with a well-choreographed series of events resulting in the cessation of normal cell function, and the ultimate disappearance of the cell. One component of apoptosis is signaling adjacent cells that this cell is committing suicide by externalizing phosphatidylserine to the outer leaflet of the cell membrane.
Annexin V
, a 32-kDa endogenous human protein, has a high affinity for membrane-bound phosphatidylserine. We have coupled
annexin V
with the bifunctional hydrazinonicotinamide reagent (HYNIC) to prepare technetium-99m HYNIC-
annexin V
and demonstrated localization of radioactivity in tissues undergoing apoptosis in vivo. In this report we describe the results of a series of experiments in mice and rats to characterize the biologic behavior of (99m)Tc-HYNIC-
annexin V
. Biodistribution studies were performed in groups of rats at 10-180 min after intravenous injection of (99m)Tc-HYNIC-
annexin V
. In order to estimate the degree of apoptosis required for localization of (99m)Tc-
annexin V
in vivo, mice were treated with dexamethasone at doses ranging from 1 to 20 mg/kg, 5 h prior to (99m)Tc-HYNIC-
annexin V
administration, to induce thymic apoptosis. Thymus was excised 1 h after radiolabeled HYNIC-
annexin V
injection; thymocytes were isolated, incubated with Hoechst 33342 followed by propidium
iodide
, and analyzed on a fluorescence-activated cell sorter. Each sorted cell population was counted in a scintillation counter. To test (99m)Tc-HYNIC-
annexin V
as a tracer for external radionuclide imaging of apoptotic cell death, radionuclide imaging of Fas-defective mice (lpr/lpr mice) and wild-type mice treated with the antibody to Fas (anti-Fas) was carried out 1 h post injection. Rat biodistribution studies demonstrated a blood clearance half-time of less than 10 min for (99m)Tc-HYNIC-
annexin V
. The kidneys had the highest concentration of radioactivity at all time points. Studies in the mouse thymus demonstrated a 40-fold increase in (99m)Tc-HYNIC-
annexin V
concentration in apoptotic thymocytes compared with the viable cell population. A correlation of r=0.78 was found between radioactivity and flow cytometric and histologic evidence of apoptosis. Imaging studies in the lpr/lpr and wild-type mice showed a substantial increase of activity in the liver of wild-type mice treated with anti-Fas, while there was no significant change, irrespective of anti-Fas administration, in lpr/lpr mice. Excellent images of hepatic apoptosis were obtained in wild-type mice 30 min after injection of (99m)Tc-HYNIC-
annexin V
. The imaging results were consistent with histologic analysis in these animals. In conlusion, these studies confirm the value of (99m)Tc-HYNIC-
annexin V
uptake as a marker for the detection and quantification of apoptotic cells in vivo.
...
PMID:Technetium-99m HYNIC-annexin V: a potential radiopharmaceutical for the in-vivo detection of apoptosis. 1054 22
Human monocyte subsets, isolated from cultures of mononuclear cells, or freshly obtained from patients with multiple sclerosis, Graves' disease or pemphigus vulgaris, differed in phenotype, apoptotic features, mRNA levels of arginase II (A-II) and the inducible form of nitric oxide synthase (iNOS). Liver-type arginase I mRNA was present in all subsets. Apoptosis was followed by the expression of T cell intracellular antigen (TIA) and the simultaneous detection of DNA stainability by propidium
iodine
and
annexin V
binding. Apoptosis was practically absent both in activated CD14(++)CD33(++)DR(++)CD25(++)CD69(++)CD71(++/+) CD16(-) cells, expressing A-II mRNA and having arginase activity, but not iNOS mRNA, and in not fully mature large CD14(++)CD16(+)CD23(+)DR(++) monocytes, expressing simultaneously both mRNAs and having both enzyme activities. However, differentiated small CD14(+/++)CD16(+)CD69(+)CD25(+/-)CD71(++)CD23(+) DR(++) monocytes, expressing high levels of iNOS mRNA, exhibited apoptotic signs. Amounts of NO synthesised by monocytes co-expressing iNOS and arginase changed with the addition of arginine or an iNOS inhibitor; in that case a correlation of NO production and apoptotic features was observed. Data suggest a regulatory role for endogenous NO in apoptosis of stimulated and differentiated monocytes, and also that iNOS and A-II, when simultaneously present, could control the production of NO as a consequence of their competition for arginine.
...
PMID:Co-expression of inducible nitric oxide synthase and arginases in different human monocyte subsets. Apoptosis regulated by endogenous NO. 1055 86
Cytolysis resulted in cell death was detected with propidium
iodide
, and apoptosis with
Annexin V
by using flow cytometry. The more vilurent strain in known murine infections showed the higher cytolytic activity. However in those mycobacterial strains that had the higher cytolytic activity on THP-1 cell, the lower level of apoptosis induction was observed. Addition of IFN-gamma or TNF-alpha to THP-1 derived macrophage did not effect on cytolytic activities nor apoptosis induction. Since mycobacteria with the higher cytolytic activity showed the lower apoptosis induction, it was suggested that apoptosis of human macrophage in mycobacterial infection is a beneficial phenomenon to the host.
...
PMID:[Factors for the onset of and the exacerbation of tuberculosis. 1. Activities in cytolysis and in apoptotic induction of mycobacteria on human THP-1 derived macrophage]. 1056 33
Growing evidence suggests that lectin-carbohydrate interactions are involved in the regulation of the balance between cell growth and programmed cell death. Viscum album agglutinin (VAA)-I is a galactoside-specific, type II ribosome-inactivating plant lectin. At concentrations less than 10 ng/ml, VAA-I has been shown to induce gene expression and secretion of proinflammatory cytokines as well as apoptosis in cultures of human peripheral blood mononuclear cells (PBMC). This study analyzes the effects of VAA-I and its recombinant nonglycosylated form (rVAA) on alterations of cell membrane permeability of cultured human peripheral lymphocytes (PBL) and on membrane exposure of phosphatidylserine characteristic of apoptosis. Analyses were performed by flow cytometry after staining with propidium
iodide
(PI) and/or with FITC-
Annexin V
/PI. After 24 h incubation of PBMC with 100 ng/ml VAA-I and rVAA, staining with supravital concentration of PI (20 microg/ml) for 1 h revealed no differences in percentages of PI-positive cells induced by the two forms of lectin (32.3% and 29.4%), but the exposure to 5 microg/ml PI for 15 min resulted in a significant difference: 35.1% and 8.0% after VAA-I and rVAA treatment, respectively. Kinetic analysis of membrane alterations showed mainly
Annexin V
positivity after 24 h, whereas after 48 h and 72 h incubation with 100 ng/ml VAA-I or rVAA loss of membrane integrity occurred, as demonstrated by PI staining. Similar to VAA-I, rVAA showed a higher binding affinity for monocytes and granulocytes than for lymphocytes. In cultures of PBL, the binding rank order of both lectins to lymphocyte subsets was NK, CD19+ > CD8+ > CD4+. The amount of Annexin/PI staining of PBL subsets corresponds to the degree of their binding capacity. In conclusion, present results demonstrate that VAA-I and its nonglycosylated recombinant form rVAA exhibit comparable effects on cell membrane alterations in the subsets of human PBLs.
...
PMID:Selective modulation of phosphatidylserine exposure on subpopulations of human peripheral blood lymphocytes by a plant lectin, Viscum album agglutinin (VAA)-I and its recombinant form (rVAA) in vitro. 1057 62
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