Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P42574 (caspase-3)
45,978 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Induction of apoptosis by different types of pathogenic retroviruses is an important step in disease development. We have observed that infection of thymic lymphocytes by the mink cell focus-forming murine leukemia virus (MCF MLV) during the preleukemic period resulted in an enhancement of apoptosis of these cells. To further study the ability of MCF MLVs to induce apoptosis and the role of this process in viral pathogenesis, we have developed an in vitro system of virus-induced apoptosis. MCF13 MLV infection of mink epithelial cells resulted in the production of cytopathic foci. In contrast, infection of mink cells with the 4070A amphotropic MLV did not produce any cytopathic effects. Staining of MCF13 MLV-infected cells with propidium iodide and annexin V-fluorescein isothiocyanate indicated that virus-induced cell death was due to apoptosis. At 6 days postinfection, the percentage of apoptotic MCF13 MLV-infected cells was 27% compared with 2 to 3% for mock- or amphotropic MLV-infected cells, representing a 9- to 14-fold difference. Assays for caspase-3 activation confirmed the detection by flow cytometry of apoptosis of MCF13 MLV-infected cells. Large amounts of unintegrated linear viral DNA were detectable by Southern blot analysis during the acute phase of infection, which indicated that MCF13 MLV is able to superinfect mink cells. Unintegrated viral DNA of only the linear form was detectable in thymic lymphocytes isolated from MCF13 MLV-inoculated mice during the preleukemic period. These results indicated that the ability of MCF13 MLV to induce apoptosis is correlated with its ability to superinfect cells and that this occurs as an early step in thymic lymphoma development.
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PMID:Mink cell focus-forming murine leukemia virus killing of mink cells involves apoptosis and superinfection. 1139 Jun 2

On the basis of in vitro inhibition of tumor cell growth, IFNs have been generally considered to be antiproliferative proteins. To probe further the potential mechanisms of the antitumor effects of IFNs, we have assessed apoptosis in response to IFN-alpha2 and IFN-beta in cell lines of varied histologies, with a focus on melanomas. Many of the cell lines tested underwent apoptosis in response to IFN-beta, as assessed both by Annexin V and terminal deoxynucleotidyl transferase-mediated nick end labeling staining. In general, IFN-beta had greater growth inhibitory and proapoptotic effects than IFN-alpha2 on all cell lines. The melanoma cell line WM9, sensitive to growth inhibition by IFNs, had a greater degree of apoptosis than A375 melanoma cells, which were largely resistant to antigrowth effects of IFNs. IFN-beta-induced apoptosis was dependent on activation of the caspase cascade with cleavage of caspases 3, 8, and 9 and of the caspase 3 substrate, poly(ADP-ribose) polymerase. Caspase inhibitors benzyloxycarbonyl-Val-Ala-Asp-fluoromethyl keton or benzyloxycarbonyl-Asp-Glu-Val-Asp-fluoromethyl keton, inhibited IFN-beta-induced apoptosis. Other changes associated with apoptosis, including the movement of cytochrome c from mitochondria to cytoplasm and DNA fragmentation, were also identified in response to IFN-beta. Apo2L ligand [tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)] was one of the early genes induced by IFN-beta in apoptosis-sensitive WM9 cells. Other sensitive melanoma cell lines had a similar IFN-beta-specific induction of TRAIL. Neutralizing antibody to TRAIL inhibited IFN-beta-induced apoptosis in WM9 cells. In resistant A375 cells, IFN-beta did not induce TRAIL/Apo2L expression. Thus, induction of TRAIL by IFNs in some tumor types may initiate the apoptotic cascade. This study offers another mechanism for the antitumor effects of IFNs.
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PMID:Preferential induction of apoptosis by interferon (IFN)-beta compared with IFN-alpha2: correlation with TRAIL/Apo2L induction in melanoma cell lines. 1141 May 25

Nitric oxide (NO) attenuates hydrogen peroxide (H2O2)-mediated injury to H9C2 cardiomyoblasts. To examine the role of nitric oxide, cultured H9C2 cardiomyoblasts were treated with H2O2 for 2 h in the presence or absence of the NO donor, diethylamine nitric oxide (DEANO). DEANO (30 microM) attenuated H2O2-induced apoptosis in H9C2 cells. H2O2-exposed H9C2 cells resulted in apoptosis in a time-dependent manner estimated by DNA fragmentation assay, nuclear morphology stained with fluorescent dye, Hoechst 33258 and Annexin V staining. Pretreatment with z-VAD-FMK, a pancaspase inhibitor, or z-DEVD-CHO, a specific caspase-3 inhibitor, completely suppressed the DNA ladder in response to H2O2. An increase in caspase-3-like protease (DEVDase) activity was observed during apoptosis, but no caspase-1 activity (YVADase) was detected. Treatment of H9C2 cells with 100 microM H2O2, resulted in a strong activation of JNK/SAPK. However, the activation of JNK/ SAPK was clearly attenuated by 30 microM DEANO. Furthermore, the dominant negative JNK and SEK1-expressing cells displayed a marked decrease in a number of apoptotic cells. This inhibition of JNK1 in the system is involved in the protection of H2O2-induced apoptosis in H9C2 cardiomyoblasts.
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PMID:Signal transduction of nitric oxide donor-induced protection in hydrogen peroxide-mediated apoptosis in H9C2 cardiomyoblasts. 1141 47

The intracellular distribution of gelsolin in NIH 3T3 cells was examined by immunostaining using affinity-purified polyclonal gelsolin antibodies before and after induction of apoptosis by serum withdrawal. Serum deprivation induced detachment of an increasing number of NIH 3T3 cells, but also apoptosis in attached cells as verified morphologically by chromatin condensation, nuclear fragmentation and labelling of their periphery by FITC-annexin V. Ongoing apoptosis was also demonstrated by activation of caspase-3 activity and chromatin cleavage into high-molecular-mass fragments, although no internucleosomal chromatin degradation (DNA-ladder formation) was detected. When cells were maintained in the presence of 10% foetal calf serum, gelsolin immunoreactivity was evenly distributed in the cytoplasm. No obvious co-localisation of gelsolin and the actin-containing stress fibres was detected under these conditions. At day one after serum withdrawal, a redistribution of gelsolin to actin filaments was detected within a few attached cells by double fluorescence staining. The number of cells exhibiting this redistribution increased at days two to four. In addition, the stress fibres increased in thickness and their length was continuously reduced. At day four, many cells contained shortened stress fibres, which had lost their longitudinal orientation. Additionally, the cytoplasm of a number of attached cells was highly condensed around their nuclei and a homogenous distribution of both gelsolin and actin was detected in the remaining cytoplasmic rim. Up to day two, these effects were reversible after re-addition of serum to attached cells. A similar redistribution of gelsolin immunore-activity was observed after induction of apoptosis by cycloheximide, but not after initiation of necrosis by hydrogen peroxide. In NIH 3T3 cells no alteration in the expression of gelsolin at the level of protein (Western blot) or specific mRNA (Northern blot) was observed after serum withdrawal. Using Western blotting, no proteolysis of gelsolin was detected up to day 4, although caspase-3 activity was found to have increased fivefold after serum withdrawal. These results suggested that in these cells F-actin severing might occur in the absence or advance of gelsolin cleavage by caspases. Intact gelsolin on its own may be sufficient for the dissolution of the microfilaments, since micro-injection of gelsolin into primary bovine lens cells led to a transient disappearance of the stress fibres and to a reduction of their attachment area to the substratum. In NIH 3T3 cells similar effects of micro-injected gelsolin were only observed at day one after serum withdrawal.
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PMID:Serum withdrawal induces a redistribution of intracellular gelsolin towards F-actin in NIH 3T3 fibroblasts preceding apoptotic cell death. 1143 27

Heart-specific inhibition of survival pathway gp130 was recently shown to sensitize transgenic mice towards stress stimuli, resulting in rapid onset of cardiac dilatation and heart failure. In order to identify further survival pathways we evaluated the role of transcription factor nuclear factor-kappa B (NF-kappa B) in tumour necrosis factor-alpha (TNF-alpha)-induced apoptosis of cardiomyocytes. TNF-alpha stimulation (10 ng/ml) of both H9c2 cells and primary cardiomyocytes isolated from neonatal Wistar rats resulted in rapid nuclear translocation of NF-kappa B complexes. The NF-kappa B complexes consisted of rel-proteins p50 and p65, as revealed by supershift analysis. Addition of proteasome inhibitor MG132 or adenoviral expression of a truncated I kappa B alpha (I kappa B Delta N) inhibited TNF-alpha-induced NF-kappa B nuclear translocation in a dose-dependent manner. Both neonatal cardiomyocytes and H9c2 cells were resistant to TNF-induced apoptosis. However, specific inhibition of NF-kappa B activation by Ad5-I kappa B alpha Delta N (MOI=50) or MG132 (5 microm) increased apoptosis as measured by subG1-assay (H9c2 cells) and annexin V binding/propidium iodide (neonatal cardiomyocytes, FACS-analysis: 7+/-2% to 26+/-5% annexin V positive/PI negative), respectively. TUNEL-assay double-stained with anti-alpha-sarcomeric actin confirmed apoptosis of neonatal cardiomyocytes. Furthermore, caspase-3 activation was increased by 52+/-7% in neonatal cardiomyocytes after TNF alpha+Ad5-I kappa B alpha Delta N compared to TNF alpha+Ad5-control treatment. Protein levels of hiAP1, hiAP2, x-iAP, bcl-2 and bcl-x(L) were neither downregulated by NF-kappa B inhibition nor upregulated by TNF-alpha stimulation. In summary, cardiomyocytes utilize transcription factor NF-kappa B to activate survival factors in the context of TNF-alpha stimulation. As locally increased levels of TNF-alpha have been detected in heart failure, NF-kappa B activity is essential for cellular homeostasis in the heart.
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PMID:Effect of NF-kappa B Inhibition on TNF-alpha-induced apoptosis and downstream pathways in cardiomyocytes. 1144 25

Helicobacter pylori has been shown to induce chronic active gastritis and peptic ulcer and may contribute to the development of duodenal ulcer. Previous studies have shown that H. pylori mediates apoptosis of gastric epithelial cells via a Fas-dependent pathway. However, evidence for the induction of such a mechanism in intestinal epithelial cells (IEC) by H. pylori infection has not been demonstrated yet. This study was performed (i) to ascertain that H. pylori can induce IEC apoptosis; (ii) to delineate the role of the cag pathogenicity island (PAI), cagE, and vacA gene products in this process; and (iii) to verify whether the Fas-dependent pathway is involved in this phenomenon. When T84 cells were exposed to VacA(+)/cag PAI(+) H. pylori strains (CCUG 17874 and 60190), they exhibited apoptosis hallmarks as assessed by morphological studies, as well as annexin V and 3,3'-dihexyloxacarbocyanine iodide staining. In contrast, few or no apoptotic features could be detected after incubation with an isogenic mutant of strain 60190 in which the cagE gene was disrupted (60190:C(-) strain) or with a VacA(-)/cag PAI(-) H. pylori strain (G21). In addition, activation of caspase-3 during infection with VacA(+)/cag PAI(+) H. pylori strains was inhibited by pretreatment of IEC with an antagonistic anti-Fas antibody (ZB4). Taken together, these findings indicate that H. pylori triggers apoptosis in IEC via a Fas-dependent pathway following a process that depends on the expression of the cag PAI.
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PMID:Epithelial intestinal cell apoptosis induced by Helicobacter pylori depends on expression of the cag pathogenicity island phenotype. 1144 79

Previous studies using transgenic mice in which metallothionein (MT) was overexpressed only in the heart have demonstrated that MT protects from oxidative cardiac injury induced by doxorubicin (DOX), an important anticancer agent. MT cardioprotection is associated with its antiapoptotic effect. The present study was undertaken to test the hypothesis that MT suppresses DOX-induced apoptosis through inhibition of mitochondrial cytochrome c release and caspase-3 activation. Primary cultures of cardiomyocytes isolated from the hearts of transgenic neonatal mice and nontransgenic controls were treated with DOX at a clinically relevant concentration (1.0 microM) for varying time periods. Apoptosis was detected in nontransgenic cardiomyocyte cultures by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling and Annexin V-fluorescein isothiocyanate binding. This apoptotic effect was significantly suppressed in the MT-overexpressing transgenic cardiomyocytes. Western blot analysis revealed that DOX caused mitochondrial cytochrome c release. Furthermore, caspase-3 activation was observed. The activation of this apoptotic pathway by DOX was dramatically inhibited in the MT-overexpressing cardiomyocytes. To elucidate the role of reactive oxygen species (ROS) in the activation of the cytochrome c-mediated caspase-3 activation pathway, the intracellular levels of ROS and their localization were detected by fluorescent confocal microscopy. Mitochondrial ROS concentrations were dramatically elevated by DOX in nontransgenic cardiomyocytes. This elevation was completely inhibited almost in the MT-overexpressing cardiomyocytes. Thus, these results demonstrate that MT suppresses DOX-induced apoptosis in cardiomyocytes through, at least in part, inhibition of the cytochrome c-mediated apoptotic pathway.
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PMID:Metallothionein inhibits doxorubicin-induced mitochondrial cytochrome c release and caspase-3 activation in cardiomyocytes. 1145 6

Astrocytes participate in a wide variety of important physiological processes and pathological insults, including ischemia. Information on the mechanism of astroglial injury and death during ischemic insult, however, is scarce. In this study, we investigated the mode of astrocytic cell death using an in vitro ischemic model. Cultured astrocytes exhibited several distinct morphological and biochemical features of apoptosis under ischemia. At 4 h of ischemia, Annexin V staining demonstrated an early commitment of some astrocytes to apoptosis. Condensed nuclei became visible from 4 h and the number increased with ischemic incubation time. Electron microscopy showed compacted and segregated chromatin along the edges of nuclear membranes. The number of TUNEL-positive nuclei and the degree of DNA laddering increased with ischemic incubation. Caspase-3, but not caspase-1, activity was increased in ischemia-injured astrocytes. Swollen mitochondria and vacuoles found in some cells with chromatin condensation indicated that these apoptotic-like cells might die of necrosis. The results imply that astrocytes are capable of undergoing apoptosis without the presence of other cell types, such as neurons. Ischemia can induce apoptosis in astrocytes contributing to the pathogenesis of ischemic injury in the CNS.
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PMID:Ischemia-induced apoptosis in primary cultures of astrocytes. 1146 Feb 68

Cyclin-dependent kinases (cdk's) have recently been suggested to regulate human immunodeficiency virus type 1 (HIV-1) transcription. Previously, we have shown that expression of one cdk inhibitor, p21/Waf1, is abrogated in HIV-1 latently infected cells. Based on this result, we investigated the transcription of HIV-1 in the presence of chemical drugs that specifically inhibited cdk activity and functionally mimicked p21/Waf1 activity. HIV-1 production in virally integrated lymphocytic and monocytic cell lines, such as ACH(2), 8E5, and U1, as well as activated peripheral blood mononuclear cells infected with syncytium-inducing (SI) or non-syncytium-inducing (NSI) HIV-1 strains, were all inhibited by Roscovitine, a purine derivative that reversibly competes for the ATP binding site present in cdk's. The decrease in viral progeny in the HIV-1-infected cells was correlated with a decrease in the transcription of HIV-1 RNAs in cells treated with Roscovitine and not with the non-cdk general cell cycle inhibitors, such as hydroxyurea (G(1)/S blocker) or nocodazole (M-phase blocker). Cyclin A- and E-associated histone H1 kinases, as well as cdk 7 and 9 activities, were all inhibited in the presence of Roscovitine. The 50% inhibitory concentration of Roscovitine on cdk's 9 and 7 was determined to be approximately 0.6 microM. Roscovitine could selectively sensitize HIV-1-infected cells to apoptosis at concentrations that did not impede the growth and proliferation of uninfected cells. Apoptosis induced by Roscovitine was found in both latent and activated infected cells, as evident by Annexin V staining and the cleavage of the PARP protein by caspase-3. More importantly, contrary to many apoptosis-inducing agents, where the apoptosis of HIV-1-infected cells accompanies production and release of infectious HIV-1 viral particles, Roscovitine treatment selectively killed HIV-1-infected cells without virion release. Collectively, our data suggest that cdk's are required for efficient HIV-1 transcription and, therefore, we propose specific cdk inhibitors as potential antiviral agents in the treatment of AIDS.
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PMID:Inhibition of human immunodeficiency virus type 1 transcription by chemical cyclin-dependent kinase inhibitors. 1146 99

While it has been claimed that some anti-endothelial cell antibodies (AECA) activate EC, there is also evidence that others trigger apoptosis. To address the issue of whether activation is a prerequisite for AECA-mediated apoptosis of EC, 23 AECA-positive sera were evaluated for their ability to induce activation and/or apoptosis. Activation was defined as an over-expression of E-selectin and intercellular adhesion molecule 1. Optical microscopy, annexin V binding, hypoploid cell enumeration, and determination of poly (ADP-ribose) polymerase cleavage-related products were used to assess apoptosis. Four functional profiles were defined: 10 sera promoted activation and apoptosis (act+/apo+), one was act+/apo-, six act-/apo+, and the remaining six act-/apo-. The reduced membrane expression of thrombomodulin was associated with apoptosis, rather than activation. Caspase-3 was implicated in the two models of apoptosis, the ratios of several survival proteins to Bax decreased, regardless of the ability of apo+ AECA to activate the cells, while radical oxygen species did not appear to be involved. Furthermore, it occurred that macrophages engulfed EC treated with apoptosis-promoting AECA, but not those incubated with AECA that did not induce apoptosis. Hence, AECA represent an extremely heterogeneous family of autoantibodies, not only because of the variety of their target antigens, but also the subsequent diversity of their effects.
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PMID:Functional heterogeneity of anti-endothelial cell antibodies. 1147 14


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