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)

Using the current blood bank storage conditions at 22 degrees C, the viability and function of human platelets can be maintained for only 5 days. This does not allow for the necessary and extensive banking of platelets needed to treat patients afflicted with thrombocytopenia, a side effect of many invasive surgeries such as cardiopulmonary bypass or bone marrow transplantation. The development of optimal techniques for long-term cryopreservation and banking of human platelets would provide the ability to greatly extend the viable life of the platelet and would fulfill an increasing and urgent need in many clinical applications. To determine the optimal techniques for platelet preservation, the expression of an activation marker, phosphatidylserine, on the platelet membrane during storage at 22 and 8 degrees C as well as during the different freezing preservation processes was examined using flow cytometry and annexin V binding assay. Human platelets were identified by both CD41 and light scatter in flow cytometry. In cryopreservation experiments, effects of the following factors on platelet activation were evaluated: (a) cryoprotective agents (CPAs) type: dimethyl sulfoxide (Me2SO), ethylene glycol (EG), and propylene glycol (PG), (b) CPA concentration ranging from 0 to 3 M, and (c) ending temperatures of a slow cooling process at -1 degrees C/min. Our results demonstrated that (a) approximately 50% of platelets were activated on days 7 and 16 at 22 and 8 degrees C, respectively; (b) platelets were not significantly activated after 30-min exposure to 1 M Me2SO, EG, and PG at 22 degrees C, respectively, and (c) there was a significant difference in cryoprotective efficacy among these three CPAs in preventing platelets from cryoinjury. After being cooled to -10 degrees C, 74% of the cryopreserved platelets survived (nonactivated) in 1 M Me2SO solution, while in 1 M EG and 1 M PG solutions, 62 and 42% of the platelets survived, respectively. Using the information that Me2SO consistently yields higher percentages of nonactivated platelets and does not seem to be cytotoxic to platelets for 30-min exposure time, this was found to be the optimal cryoprotective agent for platelets. In addition, significant Me2SO toxicity to platelets was not noted until Me2SO concentrations exceeded 2 M. Finally, a concentration of 1 M Me2SO proved to be the most effective at all cryopreservation ending temperatures tested (-10, -30, -60, and -196 degrees C). In conclusion, under the present experimental conditions, a storage temperature of 8 degrees C appeared to be much better than 22 degrees C. Although the potential chemical toxicity of 1 M Me2SO, EG, or PG is negligible, 1 M Me2SO was found to be optimum for cryopreservation of human platelets. PG has the least cryoprotective function for low-temperature platelet survival.
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PMID:Development of optimal techniques for cryopreservation of human platelets. I. Platelet activation during cold storage (at 22 and 8 degrees C) and cryopreservation. 1032 12

The effects of thrombopoietic stimulation on megakaryocytopoiesis, platelet production, and platelet viability and function were examined in normal volunteers randomized to receive single bolus subcutaneous injections of 3 microg/kg pegylated recombinant megakaryocyte growth and development factor (PEG-rHuMGDF) or placebo in a 3:1 ratio. PEG-rHuMGDF transiently doubled circulating platelet counts, from 237 +/- 41 x 10(3)/microL to 522 +/- 90 x 10(3)/microL (P <.0001), peaking on day 12. Baseline and day-12 samples showed no differences in responsiveness of platelets to adenosine diphosphate or thrombin receptor agonist peptide (P >.4 in all cases); expression of platelet ligand-induced binding sites or annexin V binding sites (P >.6 in both cases); or density of platelet TPO-receptors (P >.5). Platelet counts normalized by day 28. The life span of autologous (111)In-labeled platelets increased from 205 +/- 18 hours (baseline) to 226 +/- 22 hours (P <.01) on day 8. Platelet life span decreased from 226 +/- 22 hours (day 8) to 178 +/- 53 hours (P <.05) on day 18. The theoretical basis for senescent changes in mean platelet life span was illustrated by biomathematical modeling. Platelet turnover increased from 43.9 +/- 11.9 x 10(3) platelets/microL/d (baseline) to 101 +/- 27.6 x 10(3) platelets/microL/d (P =.0009), and marrow megakaryocyte mass expanded from 37.4 +/- 18.5 fL/kg to 62 +/- 17 x 10(10) fL/kg (P =. 015). Although PEG-rHuMGDF initially increased megakaryocyte volume and ploidy, subsequently ploidy showed a transient reciprocal decrease when the platelet counts exceeded placebo values. In healthy human volunteers PEG-rHuMGDF transiently increases megakaryocytopoiesis 2-fold. Additionally, peripheral platelets expand correspondingly and exhibit normal function and viability during the ensuing 10 days. The induced perturbation in steady state thrombopoiesis resolves by 4 weeks. (Blood. 2000;95:2514-2522)
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PMID:Effects of megakaryocyte growth and development factor on platelet production, platelet life span, and platelet function in healthy human volunteers. 1075 29

This study was designed to examine the role of opioids in cell survival, with an emphasis on the mechanism of opioid growth factor (OGF, [Met(5)]-enkephalin)-dependent growth inhibition. Using three human cancer cell lines: MIA PaCa-2 pancreatic adenocarcinoma, HT-29 colon adenocarcinoma, and CAL-27 squamous cell carcinoma of the head and neck, and OGF and the opioid antagonist naltrexone (NTX) at a dosage (10(-6)M) selected because it is known to repress or increase, respectively, cell replication, the effects on apoptosis (TUNEL, Annexin V) and necrosis (trypan blue) were investigated on days 2, 5, and 7 of exposure. In addition, the influence of a variety of other natural and synthetic opioids on apoptosis and necrosis was examined at a dosage of 10(-6)M. OGF, NTX, naloxone, [D-Pen(2,5)]-enkephalin, [Leu(5)]-enkephalin, dynorphin A1-8, beta-endorphin, endomorphin-1 and -2, and methadone at concentrations of 10(-6)M did not alter cell viability of any cancer cell line. Exposure of cultures to [D-Ala(2),MePhe(4),Glycol(5)]-enkephalin (DAMGO), morphine, or etorphine at 10(-6)M significantly increased the number of adherent cells positively stained for TUNEL and Annexin V, as well as the number of necrotic cells in the supernatant, from control levels at all time points studied. The effects of DAMGO, morphine, and etorphine on apoptosis/necrosis were not fully blocked by concomitant administration of naloxone. Despite the increase in cell death in some opioid-treated groups, the number of apoptotic and necrotic adherent cells, and the number of necrotic cells in the supernatant, was no more than 1-2% of the total cell population. These results indicate that the inhibitory (OGF) or stimulatory (NTX) action on cell growth in tissue culture is not due to alterations in apoptotic or necrotic pathways. Moreover, although some opioids increased cell death, and dose-effect relationships need to be established, this activity was not of great magnitude and supports the previously reported lack of growth inhibition of many of these compounds.
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PMID:Opioids and the apoptotic pathway in human cancer cells. 1274 39

The relative activities of interferon-alpha2b (IFN-alpha2b) and polyethylene glycol(12000)-IFN-alpha2b (PEG-IFN-alpha2b) were assessed in cell culture studies using WM9 melanoma or ACHN renal cell carcinoma cell lines. Interferon-alpha2b and PEG-IFN-alpha2b had identical antiproliferative activities when tested in cell proliferation studies conducted with equivalent antiviral units of each IFN preparation. Neither IFN formulation was effective in inducing apoptosis in WM9 melanoma cells, but both increased slightly the percentage of ACHN cells undergoing apoptosis as assessed by Annexin V staining. Interferon-alpha2b and PEG-IFN-alpha2b both activated signal transducer and activator of transcription complexes, and the duration of complex activation was similar for both IFN formulations. Induction of different IFN-stimulated genes was assessed by Northern blotting and the quantitative real-time reverse transcription-coupled polymerase chain reaction (RT-PCR) in WM9 melanoma, ACHN renal cell carcinoma, U937 lymphoma, and MOLT-4 and Mono Mac 6 leukemia cell lines. Interferon-alpha2b and PEG-IFN-alpha2b had equivalent gene-modulatory activities within each of these tumor cell lines, although cell line-specific induction patterns were observed. When compared with the antiviral 50% inhibitory concentration (IC(50)) values, the dose-dependent gene expression data correlated with cell sensitivity to IFN treatment. Together, the drug comparability and cell sensitivity data suggest a predictive relation between dose, time, antiviral activity, and gene transcription effects. Therefore, although the specific activity of IFN-alpha2b is approximately three times greater than PEG-IFN-alpha2b, the two preparations have identical in vitro biologic activities when applied to cells at equivalent antiviral units.
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PMID:Biologic activity of polyethylene glycol12000-interferon-alpha2b compared with interferon-alpha2b: gene modulatory and antigrowth effects in tumor cells. 1280 74

We have developed a one-step procedure to introduce both polyethylene glycol (PEG) and the metal chelator diethylenetriaminepentaacetic acid (DTPA) to proteins through a heterofunctional PEG precursor. The PEG precursor contains DTPA at one end and an amine-reactive isothiocyanate (SCN-) functional group at the other end. It was obtained as lyophilized powder and could be stored at 4 degrees C for several months. Protein conjugation was achieved by simply mixing the proteins and the PEG precursor SCN-PEG-DTPA in an aqueous solution. As exemplified by the PEGylation and radiolabeling of annexin V, the resulting conjugate 111In-DTPA-PEG-annexin V showed selective binding to apoptotic cells in vitro and increased blood half-life in vivo. The PEGylated, radiolabeled annexin V may be useful in the noninvasive imaging of apoptosis.
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PMID:Improved radiolabeling of PEGylated protein: PEGylated annexin V for noninvasive imaging of tumor apoptosis. 1462 30

Heme oxygenase-1 (HO-1), an inducible enzyme that catalyzes oxidative degradation of heme to form biliverdin, carbon monoxide and free iron, may protect tumor cells against oxidative stress, thus contributing to rapid tumor growth in vivo. Here, we discuss whether pegylated zinc protoporphyrin (PEG-ZnPP), a potent HO inhibitor, modulates the chemotherapeutic response of tumor cells to treatment that generates reactive oxygen species (ROS). PEG-ZnPP is a water-soluble HO inhibitor that accumulates in tumor tissues after intravenous administration. Cytotoxicity of antitumor agents in vitro was determined by means of MTT and annexin V assays using human colon carcinoma SW480 cells. Mice bearing sarcoma 180 tumors were used as an in vivo model. Pegylated D-amino acid oxidase (PEG-DAO), which behaves as an oxidative chemotherapeutic agent by generating toxic oxidants at tumor tissues, was administered with its substrate D-proline to mice with or without PEG-ZnPP pretreatment. PEG-ZnPP-treated SW480 cells became vulnerable to insults caused by various cytotoxic agents; the 50% lethal doses were reduced by 25%, 39%, 83%, and 61% for hydrogen peroxide, t-butyl hydroperoxide, camptothecin and doxorubicin, respectively. Cells treated with PEG-ZnPP plus cytotoxic oxidants exhibited marked production of intracellular ROS, which paralleled the incidence of apoptosis. PEG-ZnPP pretreatment significantly reduced tumor growth in mice receiving PEG-DAO/D-proline compared to no PEG-ZnPP pretreatment. These findings suggest that HO-1 may become an attractive target for chemotherapeutic intervention. Further study of the effect of PEG-ZnPP plus conventional anticancer drugs that generate ROS, such as cisplatin, camptothecin, doxorubicin, mitomycin C and etoposide, is warranted.
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PMID:Enhancement of chemotherapeutic response of tumor cells by a heme oxygenase inhibitor, pegylated zinc protoporphyrin. 1473 61

This review provides a critical and thorough overview of the radiopharmaceutical development and in vivo evaluation of all apoptosis-detecting radioligands that have emerged so far, along with their possible applications in nuclear medicine. The following SPECT and PET radioligands are discussed: all forms of halogenated Annexin V (i.e. (123)I-labelled, (124)I-labelled, (125)I-labelled, (18)F-labelled), (99m)Tc/(94m)Tc-labelled Annexin V derivatives using different chelators and co-ligands (i.e. BTAP, Hynic, iminothiolane, MAG(3), EDDA, EC, tricarbonyl, SDH) or direct (99m)Tc-labelling, (99m)Tc-labelled Annexin V mutants and (99m)Tc/(18)F-radiopeptide constructs (i.e. AFIM molecules), (111)In-DTPA-PEG-Annexin V, (11)C-Annexin V and (64)Cu-, (67)Ga- and (68)Ga-DOTA-Annexin V. In addition, the potential role and clinical relevance of anti-PS monoclonal antibodies and other alternative apoptosis markers are reviewed, including: anti-Annexin V monoclonal antibodies, radiolabelled caspase inhibitors and substrates and mitochondrial membrane permeability targeting radioligands. Nevertheless, major emphasis is placed on the group of Annexin V-based radioligands, in particular (99m)Tc-Hynic-Annexin V, since this molecule is by far the most extensively investigated and best-characterised apoptosis marker at present. Furthermore, the newly emerging imaging modalities for in vivo detection of programmed cell death, such as MRI, MRS, optical, bioluminescent and ultrasound imaging, are briefly described. Finally, some future perspectives are presented with the aim of promoting the development of potential new strategies in pursuit of the ideal cell death-detecting radioligand.
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PMID:Apoptosis-detecting radioligands: current state of the art and future perspectives. 1572 55

Bovine serum amine oxidase (BSAO) oxidatively deaminates polyamines containing primary amine groups, spermidine and spermine, to form the cytotoxic products hydrogen peroxide and aldehyde(s). Polyamines are present at elevated levels in many tumor tissues. The aims of the study were to evaluate the anti-tumoral activities of native and immobilized BSAO in mouse melanoma and also to determine the mechanism of tumor cell death. C57BL mice received a subcutaneous injection of B16 melanoma cells to induce formation of tumors, prior to antitumor treatments with native and immobilized BSAO. The enzyme was immobilized in a poly(ethylene glycol) (PEG) biocompatible matrix. Antitumor treatments consisted of a single injection of enzyme into the tumor. When immobilized BSAO (2.5mU) was injected into the tumor, there was a marked decrease of 70% of the tumor growth. This was compared with a decrease of only 32% of tumor size when the same amount of native BSAO was administered. The type of cell death was analysed in tumors that were treated with native or immobilized BSAO. When tumors were treated with immobilized BSAO, there was induction of a high level of apoptosis (around 70%), compared to less than 10% with the native enzyme. Apoptotic cell death was assessed by nuclear chromatin condensation using Hoechst staining and labelling of externalized phosphatidylserine using Annexin V. However, native BSAO, probably due to a burst of cytotoxic products, induced a high level of necrosis of about 40%, compared to less than 10% with immobilized BSAO. In conclusion, the advantage is that immobilized BSAO can act by allowing the slow release of cytotoxic products, which induces tumor cell death by apoptosis rather than necrosis.
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PMID:Anti-tumoral effect of native and immobilized bovine serum amine oxidase in a mouse melanoma model. 1593 45

p53 is activated genetically by a set of kinases that are components of the calcium calmodulin kinase superfamily, including CHK2, AMP kinase, and DAPK-1. In dissecting the mechanism of DAPK-1 control, a novel mutation (N1347S) was identified in the death domain of DAPK-1. The N1347S mutation prevented the death domain module binding stably to ERK in vitro and in vivo. Gel filtration demonstrated that the N1347S mutation disrupted the higher order oligomeric nature of the purified recombinant death domain miniprotein. Accordingly, the N1347S death domain module is defective in vivo in the formation of high molecular weight oligomeric intermediates after cross-linking with ethylene glycol bis(succinimidylsuccinate). Full-length DAPK-1 protein harboring a N1347S mutation in the death domain was also defective in binding to ERK in cells and was defective in formation of an ethylene glycol bis(succinimidylsuccinate)-cross-linked intermediate in vivo. Full-length DAPK-1 encoding the N1347S mutation was attenuated in tumor necrosis factor receptor-induced apoptosis. However, the N1347S mutation strikingly prevented ERK:DAPK-1-dependent apoptosis as defined by poly(ADP-ribose) polymerase cleavage, Annexin V staining, and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling imaging. Significant penetrance of the N1347S allele was identified in normal genomic DNA indicating the mutation is germ line, not tumor derived. The frequency observed in genomic DNA was from 37 to 45% for homozygous wild-type, 41 to 47% for heterozygotes, and 12 to 15% for homozygous mutant. These data highlight a naturally occurring DAPK-1 mutation that alters the oligomeric structure of the death domain, de-stabilizes DAPK-1 binding to ERK, and prevents ERK:DAPK-1-dependent apoptosis.
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PMID:A germ line mutation in the death domain of DAPK-1 inactivates ERK-induced apoptosis. 1724 21

Curcumin, a major pigment of turmeric, is a natural antioxidant possessing a variety of pharmacological activities and therapeutic properties. But its mechanisms are unknown. In our previous study, we found that a 2-h exposure to curcumin induced DNA damage to both the mitochondrial DNA (mtDNA) and the nuclear DNA (nDNA) in HepG2 cells and that mtDNA damage was more extensive than nDNA damage. Therefore, experiments were initiated to evaluate the role of mtDNA damage in curcumin-induced apoptosis. The results demonstrated that HepG2 cells challenged with curcumin for 1 h showed a transient elevation of the mitochondrial membrane potential (DeltaPsim), followed by cytochrome c release into the cytosol and disruption of DeltaPsim after 6 h exposure to curcumin. Apoptosis was detected by Hoechst 33342 and annexin V/PI assay after 10 h treatment. Interestingly, the expression of Bcl-2 remained unchanged. A resistance to apoptosis for the corresponding rho0 counterparts confirmed a critical dependency for mitochondria during the induction of apoptosis in HepG2 cells mediated by curcumin. The effects of PEG-SOD in protecting against curcumin-induced cytotoxicity suggest that curcumin-induced cytotoxicity is directly dependent on superoxide anion O2- production. These data suggest that mitochondrial hyperpolarization is a prerequisite for curcumin-induced apoptosis and that mtDNA damage is the initial event triggering a chain of events leading to apoptosis in HepG2 cells.
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PMID:Curcumin induces apoptosis through mitochondrial hyperpolarization and mtDNA damage in human hepatoma G2 cells. 1769 41


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