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Query: UNIPROT:P08758 (
annexin V
)
9,383
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
We investigated whether p53, being a redox-sensitive protein, has a role in the responsiveness of AML cells to etoposide. Two subclones of the OCI/AML-2 cell line, the etoposide-sensitive (ES) and the etoposide-resistant (ER), were used as models. Sensitivity to etoposide was measured by trypan blue and
annexin V
assays. Etoposide-induced peroxide formation was associated with the induction of cell death. Evident expression of mutated p53 was observed in both subclones in basal growth conditions as analysed by Western blotting and flow cytometry. After etoposide exposure for up to 24 hours, some nuclear accumulation of p53 was observed in the ER subclone, as analysed by Western blotting. The conformation of p53, however, was not changed from mutated toward wild-type during exposure in either of the subclones as analysed by flow cytometry. In conclusion, etoposide-induced change in cellular redox state was associated with apoptosis, but was not a sufficient stimulus for p53 to make its conformation active. Thus, mutated p53 seems to have no role in etoposide-induced apoptosis.
Leuk Res 2001
Dec
PMID:p53 and redox state in etoposide-induced acute myeloblastic leukemia cell death. 1168 84
Apoptosis contributes to myocardial cell death during ischemia and reperfusion, especially during reperfusion. Growth factor "survival" signaling attenuates apoptosis. We therefore examined the effects of transforming growth factor-beta1 (TGF-beta1) on reperfusion injury and assessed the role of p42/p44 MAPK signaling in TGF-beta1-induced protection. Rat ventricular myocytes were subjected to hypoxia and reoxygenation. TGF-beta1 (0.2 ng/ml) was applied to cells during reoxygenation and the extent of apoptosis was determined by TUNEL and
annexin V
binding assays. Further studies were conducted in intact rat hearts subjected to regional ischemia and reperfusion. TGF-beta1 (0.2 ng/ml) was perfused during early reperfusion. In cells, incubation with TGF-beta1 (0.2 ng/ml) during reoxygenation attenuated the extent of cell membrane damage (trypan blue uptake) and also reduced the numbers of TUNEL-and
annexin V
-positive cells. Reduction of apoptosis was abrogated by PD98059 (5 microM), an inhibitor of p42/p44 MAPK activation. TGF-beta1 activated p42/p44 MAPK transiently in normoxic myocytes. When intact hearts received TGF-beta1 (0.2 ng/ml) during early reperfusion, infarct size was reduced from 39.4 +/- 3.1% to 17.3 +/- 3.1% (p < 0.01). This protective action of TGF-beta1 was abrogated by PD98059. These studies are the first to show that TGF-beta attenuates cardiac myocyte apoptosis during early reperfusion and limits infarct size through p42/p44 MAPK activation.
J Cardiovasc Pharmacol 2001
Dec
PMID:Cardioprotective effects of transforming growth factor-beta1 during early reoxygenation or reperfusion are mediated by p42/p44 MAPK. 1170 97
The pathogenic role of anti-
annexin V
antibodies remains unclear. Anti-
annexin V
antibodies are frequently associated with higher incidences of intrauterine fetal loss, preeclampsia, and arterial and venous thrombosis. The present study investigated the in vitro ability of anti-
annexin V
antibody to bind human trophoblast cells, to affect trophoblast gonadotropin secretion and invasiveness, and to induce placental apoptosis. Cytotrophoblast cells were dispersed in Ringer bicarbonate buffer containing trypsin and DNase I, filtered, and layered over a Percoll gradient in Hanks balanced salt solution. In the case of monoclonal anti-
annexin V
antibody, the highest binding was found when the cells displayed the greatest amount of syncytium formation. Anti-
annexin V
antibody, but not its negative control, induced trophoblast apoptosis and significantly reduced trophoblast gonadotropin secretion. These findings suggest that recognition by anti-
annexin V
antibody of adhered
annexin V
on trophoblast cell structures might represent a potential pathogenic mechanism by which these antibodies can cause defective placentation.
Biol Reprod 2001
Dec
PMID:Monoclonal anti-annexin V antibody inhibits trophoblast gonadotropin secretion and induces syncytiotrophoblast apoptosis. 1171 39
Cyclophosphamide (CPA), a widely used oxazaphosphorine anti-cancer prodrug, is inactive until it is metabolized by cytochrome P450 to yield phosphoramide mustard and acrolein, which alkylate DNA and proteins, respectively. Tumor cells transduced with the human cytochrome P450 gene CYP2B6 are greatly sensitized to CPA, however, the pathway of CPA-induced cell death is unknown. The present study investigates the cytotoxic events induced by CPA in 9L gliosarcoma cells retrovirally transduced with CYP2B6, or induced in wild-type 9L cells treated with mafosfamide (MFA) or 4-hydroperoxyifosfamide (4OOH-IFA), chemically activated forms of CPA and its isomer ifosfamide. CPA and MFA were both shown to effect tumor cell death by stimulating apoptosis, as evidenced by the induction of plasma membrane blebbing, DNA fragmentation, and cleavage of the caspase 3 and caspase 7 substrate poly(ADP-ribose) polymerase (PARP) in drug-treated cells. Caspase 9 was identified as the regulatory upstream caspase activated in 9L cells treated with CPA, MFA, or 4OOH-IFA, implicating the mitochondrial apoptotic pathway in oxazaphosphorine-induced tumor cell death. Correspondingly, expression of the mitochondrial proapoptotic factor Bax enhanced caspase 9 activation, plasma membrane blebbing, and drug-induced cytotoxicity. Conversely, overexpression of the mitochondrial antiapoptotic factor Bcl-2 blocked caspase 9 activation, leading to an inhibition of drug-induced plasma membrane permeability and blebbing, terminal deoxynucleotidyl transferase dUTP nick-end labeling positivity, PARP cleavage,
Annexin V
positivity, and drug-induced cell death. Although Bcl-2 thus blocked the cytotoxic effects of activated CPA, it did not inhibit the drug's cytostatic effects. CPA induced S-phase cell cycle arrest followed by conversion to an apoptotic pre-G1 state in wild-type 9L cells; by contrast, Bcl-2-expressing 9L cells accumulated in G2/M in response to CPA treatment. Intratumoral expression of Bcl-2 and related family members, including both apoptotic and antiapoptotic factors, is thus an important determinant of the responsiveness of tumor cells to CPA and ifosfamide, both in the context of conventional chemotherapy and in patients sensitized to these oxazaphosphorine drugs by the use of cytochrome P450-based gene therapy.
Mol Pharmacol 2001
Dec
PMID:Cyclophosphamide induces caspase 9-dependent apoptosis in 9L tumor cells. 1172 34
The family of autoantibodies known as antiphospholipid antibodies (aPL) and the lupus anticoagulant (LA) are associated with a spectrum of clinical manifestations including life-threatening thrombosis. While our current knowledge of thrombosis is imperfect and the mere presence of aPL is imprecisely associated with clinical events, our knowledge in this area has greatly expanded in recent years. It is clear that high levels of IgG aPL are associated with an increased risk of thrombosis. In 1990, investigators demonstrated that some aPL are directed against the beta2-Glycoprotein I (beta2-GPI) 50 kDa subunit and reported that these showed concordance with risk of clotting in certain groups of patients. Studies have also demonstrated that aPL reacted with antigens other than beta2-GPI, namely prothrombin,
annexin V
, protein S, protein C and high molecular weight kininogen. We review the clinical features of the antiphospholipid syndrome (APS), including vascular occlusion, pregnancy loss, thrombocytopenia and catastrophic APS. We also review the role of antibodies in the pathogenesis of APS as well as the spectrum of autoantibodies that have been found in APS.
Front Biosci 2001
Dec
01
PMID:Antiphospholipid antibodies in systemic lupus erythematosus and the antiphospholipid syndrome. 1172 83
Exposure of renal medullary cells to elevated extracellular NaCl concentrations is associated with increased heat shock protein 72 (HSP72) expression and improved resistance to subsequent exposure to a high urea concentration (600 mM). To establish a causal relationship between HSP72 expression and protection against high urea concentrations, HSP72 was inducibly overexpressed in Madin-Darby canine kidney (MDCK) cells, in the absence of hypertonic stress before urea exposure. For this purpose, the human stress-inducible HSP72 gene was cloned downstream from a dexamethasone (DEX)-inducible promoter in the eukaryotic expression vector pLKneo. This construct allowed robust induction of HSP72 by exposure of stably transfected MDCK cells (MDCK-LK72) to 0.1 microM DEX. Increased HSP72 abundance significantly improved survival rates after 24-h exposure of the cells to medium containing 600 mM urea (14 versus 43%). In mock-transfected or wild-type cells, DEX had no significant effect on HSP72 abundance or urea resistance. In accordance with those findings, lactate dehydrogenase activity in the supernatant was significantly reduced, compared with appropriate control samples, only in MDCK-LK72 cells overexpressing HSP72. Labeling with
annexin V
-FITC and propidium iodide, followed by flow cytometry, revealed that overexpression of HSP72 was associated with a reduction in the number of apoptotic-lysed cells, a concomitant retardation of apoptosis, and an increase in the number of viable cells. These data support the view that HSP72, which is very abundant in the renal inner medulla, is an important component of the defense mechanism of medullary cells against extreme concentrations of urea.
J Am Soc Nephrol 2001
Dec
PMID:Regulated overexpression of heat shock protein 72 protects Madin-Darby canine kidney cells from the detrimental effects of high urea concentrations. 1172 24
Cisplatin is a potent chemotherapeutic agent that is used to treat many human malignancies. Unfortunately, in addition to side effects such as ototoxicity, anaphylaxis, and bone marrow suppression, a significant percentage of patients receiving cisplatin develop severe nephrotoxicity. Mitochondrial dysfunction that is mediated via the generation of reactive oxygen species has been implicated in the pathogenesis of cisplatin-induced renal injury. To address the mechanism, it was hypothesized that overexpression of antioxidant enzymes, such as mitochondria-localized manganese superoxide dismutase (MnSOD) or mitochondria-targeted catalase (mito-Cat), would be cytoprotective in cisplatin-induced cell injury. To this end, human MnSOD or a mito-Cat vector were stably transfected into human embryonic kidney 293 cells. Cells that overexpressed MnSOD exhibited significantly less cell rounding and detachment compared with both mito-Cat and vector controls after exposure to 20 microM cisplatin. Cell injury as assessed by DNA fragmentation and
annexin V
binding assays was significantly decreased in the cells that overexpressed MnSOD compared with vector alone and mito-Cat. In addition, elevated levels of MnSOD were strongly associated with increased clonogenic potential after cisplatin challenge. Thus, overexpression of MnSOD, and not catalase, protects against cisplatin-induced renal epithelial cell injury. These results demonstrate the importance of reactive oxygen species in the mechanism that underlies cisplatin-induced renal injury and specifically implicate the superoxide radical, and not hydrogen peroxide, as the mediator.
J Am Soc Nephrol 2001
Dec
PMID:Manganese superoxide dismutase attenuates Cisplatin-induced renal injury: importance of superoxide. 1172 37
Interleukin-5 (IL-5) transgenic mice were used to assess the immunological features of CSF eosinophils from mice infected with Angiostrongylus cantonensis. CSF eosinophils were hypodense by day 14 post infection (p.i.). CSF eosinophils survived longer in vitro than peritoneal eosinophils collected from cadmium sulphate (CdSO(4)) -treated normal IL-5 transgenic mice. Apoptosis was measured by
Annexin V
binding and the presence of a distinct laddering pattern of DNA fragmentation on agarose electrophoresis. Regardless of the presence or absence of Actinomycin D, CSF eosinophils collected from IL-5 transgenic mice from days 15-36 p.i. exhibited less apoptosis than peritoneal eosinophils collected from uninfected IL-5 transgenic mice. CSF eosinophils collected from A. cantonensis infected C57BL/6 mice at days 15-34 p.i. showed elongation of survival time and less apoptosis during in vitro cultivation. Reduced apoptosis was noted only in CSF eosinophils, but not in peritoneal eosinophils recovered from the same infected IL-5 transgenic mice. CPP32/Caspase 3 activity of cultured peritoneal eosinophils from both infected and uninfected IL-5 transgenic mice was higher than that of cultured CSF eosinophils. Stimulation with A23187 readily induced apoptosis of peritoneal eosinophils, but not CSF eosinophils or peritoneal eosinophils cultured with mouse recombinant IL-5. The latter cells were morphologically identical to hypodense eosinophils. RT-PCR analysis indicated that bcl-2 and bcl-x(L) mRNA expression was higher in CSF eosinophils compared with peritoneal eosinophils and this expression in the latter cells was upregulated after culture with mouse recombinant IL-5. These results suggest that CSF eosinophils, shifting to hypodense status through an accumulation from peripheral blood, are resistant to apoptosis. These changes may explain the long-lasting, helminthotoxic and neurotoxic actions of CSF eosinophils in A. cantonensis infection.
Int J Parasitol 2001
Dec
PMID:Eosinophils in the cerebrospinal fluid of mice infected with Angiostrongylus cantonensis are resistant to apoptosis. 1173 Jul 92
Annexin A5
(
annexin V
,
anchorin CII
) represents the prototype member of the large annexin family, characterized by its ability to interact with phospholipids in a calcium-dependent manner and to form calcium-specific ion channels. Despite intense biochemical analysis, the in vivo expression and function of this annexin during mouse development, still remains unclear. Immunohistochemistry, in situ hybridization and reporter gene expression were used to define expression of annexin A5 during early mouse development. First, annexin A5 expression is associated with the developing vascular system. Later, expression is detected within the notochord and found in parallel to the differentiation of cartilage and bone. Therefore, expression of the Anxa5 gene may represent a novel marker characterizing cell lineages involved in the development of the vascular as well as the skeletal system.
Mech Dev 2001
Dec
PMID:Sequential expression of annexin A5 in the vasculature and skeletal elements during mouse development. 1173 Dec 55
The role of reactive oxygen species (ROS) in the pathogenesis of vascular diseases is well established, but few data exist on the mechanisms by which ROS induce endothelial cell (EC) death. We examined the conditions and the mechanisms by which oxidative stress induces EC death, using cultured confluent bovine aortic ECs exposed for 30 min to different concentrations of hydroxyl radicals (HO*) generated by hydrogen peroxide (H(2)O(2)) in the presence of 100 microM ferrous sulfate (FeSO(4)). Cell viability assays, Hoechst DNA staining, TUNEL (TDT-mediated dUTP-biotin nick end-labeling) analysis, agarose gel electrophoresis and
annexin V
assay were used to determine the effect of HO* on the viability of ECs, and to distinguish between apoptosis and necrosis. The results showed that at concentrations of up to 0.1 mM H(2)O(2)/FeSO(4), the large majority of cells are viable, except for approximately 12.5% death, which occurs by apoptosis. At a concentration of 0.2 mM H(2)O(2), the cell viability is reduced to 66%, while EC apoptosis remained at comparable values (14%). At high oxidative stress (0.5 mM H(2)O(2)), the cell viability was drastically reduced (approximately 39%), and the prevalent form of death was necrosis; apoptosis accounted for only approximately 17%. Together, these data indicate that: (1) HO* induce EC death either by apoptosis or necrosis and (2) the mechanisms of EC death differ as a function of the concentration of HO. Thus, the same insult can cause apoptosis and/or necrosis, as a function of the intensity rather than the nature of the insult.
Cell Tissue Res 2001
Dec
PMID:Severity of oxidative stress generates different mechanisms of endothelial cell death. 1173 41
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