Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.22.56 (caspase-3)
 35,750 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We examined the action of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) on HeLa cells and compared it with that of cisplatin (CP). MNNG directly killed a substantial number of cells within 1 hour and resulted in strong DNA-damage as evidenced by Comet measurements. Despite appearance of DNA lesions, p53 protein was not activated. Analysis of HeLa cells treated with MNNG for 1h, 3h and 6h by flow cytometry and by Hoechst staining did not reveal any sub-G(1) cell population and chromatin condensation/fragmentation characteristic for apoptosis, respectively. Also, no biochemical changes typical for apoptosis such as activation of caspase-3 or release of cytochrome C from mitochondria were detected. Inactivation of PARP-1 reduced the direct cytotoxicity exerted by MNNG. Our results showing that despite appearance of severe DNA lesions after short exposure of HeLa cells to MNNG neither activation of p53 response nor induction of apoptosis occurred implicate that generation of strong DNA damage is not sufficient to stabilize p53 protein in HeLa cells. Our data unequivocally show that the conscientious determination of the type of cell death induced by genotoxic agents is necessary. The assessment of the changes based on at least a few independent criteria is required to discriminate between apoptosis and necrosis. Since the alkylating agents generate DNA strand breaks, the recruitment of methods based on determination of DNA cleavage such as DNA ladder or TUNEL assay for evaluation of apoptosis is not adequate.
 ...
PMID:Non-apoptogenic killing of hela cervical carcinoma cells after short exposure to the alkylating agent N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). 1289 20

Cytosine arabinoside (ara-C) is a nucleoside analog used in the treatment of hematologic malignancies. One of the major side effects of ara-C chemotherapy is neurotoxicity. In this study, we have further characterized the cell death induced by ara-C in sympathetic neurons. Similar to neurons undergoing trophic factor deprivation-induced apoptosis, ara-C-exposed neurons became hypometabolic before death and upregulated c-myb, c-fos, and Bim. Bax deletion delayed, but did not prevent, ara-C toxicity. Neurons died by apoptosis, indicated by the release of mitochondrial cytochrome-c and caspase-3 activation. p53-deficient neurons demonstrated decreased sensitivity to ara-C, but neither p53 nor multiple p53-regulated genes were induced. Mature neurons showed increased ara-C resistance. These results demonstrate that molecular mechanisms underlying ara-C-induced death are similar to those responsible for trophic factor deprivation-induced apoptosis. However, substantial differences in neuronal death after these two distinct stress stimuli exist since ara-C toxicity, unlike the developmental death, can proceed in the absence of Bax.
 ...
PMID:Cytosine arabinoside rapidly activates Bax-dependent apoptosis and a delayed Bax-independent death pathway in sympathetic neurons. 1293 79

Ultraviolet (UV) light is a strong apoptotic trigger that induces caspase-dependent biochemical changes in cells. Previously we showed that UV irradiation can activate caspase-3, and the subsequent cleavage and activation of p21(Cdc42/Rac)-activated kinase 2 (PAK2) in human epidermoid carcinoma A431 cells. In this study we demonstrate that curcumin (Cur), the yellow pigment of Curcuma longa with known anti-oxidant and anti-inflammatory properties, can prevent UV irradiation-induced apoptotic changes, including c-Jun N-terminal kinase (JNK) activation, loss of mitochondrial membrane potential (MMP), mitochondrial release of cytochrome C, caspase-3 activation, and cleavage/activation of PAK2 in A431 cells. Flow cytometric analysis using the cell permeable dye 2',7'-dichlorofluorescin diacetate (DCF-DA) as an indicator of reactive oxygen species (ROS) generation revealed that the increase in intracellular oxidative stress caused by UV irradiation could be abolished by Cur. In addition, we found that SP600125, a JNK-specific inhibitor, reduced UV irradiation-induced JNK activation as well as caspase-3 activation, indicating that JNK activity is required for UV irradiation-induced caspase activation. Collectively, our results demonstrate that Cur significantly attenuates UV irradiation-induced ROS formation, and suggest that ROS triggers JNK activation, which in turn causes MMP change, cytochrome C release, caspase activation, and subsequent apoptotic biochemical changes.
 ...
PMID:Curcumin inhibits UV irradiation-induced oxidative stress and apoptotic biochemical changes in human epidermoid carcinoma A431 cells. 1450 49

This in vitro study was designed to examine the efficacy of exogenous pyruvate and glucose as a fuel substrate to protect rat astrocytes from post-ischemic injury. Astrocytes were incubated in Kreb's buffer deprived of oxygen and glucose for 6 h (ischemia) followed by incubation with added pyruvate or glucose and normoxia for the next 6 h (reperfusion). The transformation of reactive astrocytes in response to various treatments was examined by immunostaining with glial fibrillary acidic protein. The extent of cell damage was evaluated in terms of lactate dehydrogenase leakage from the cells and altered intracellular redox status. The mechanism of cell death was determined by immunoblotting with cytochrome C, caspase-3 and PARP antibodies. The mechanism of the action of pyruvate was determined by measuring the activity of pyruvate dehydrogenase complex, and cellular metabolic status by measuring ATP levels. In comparison to glucose, supply of exogenous pyruvate restored the morphological integrity of post-ischemic astrocytes and prevented gliosis. Pyruvate prevented the cell death of post-ischemic astrocytes by inhibiting the leakage of lactate dehydrogenase, decreasing the redox ratio and restraining the activation of apoptotic events such as release of mitochondrial cytochrome c and fragmentation of caspase-3 and PARP. This study also suggests that pyruvate may accelerate its own metabolism by increasing the activity of pyruvate dehydrogenase and thus restores the cellular ATP levels in post-ischemic astrocytes. Use of pyruvate as an alternate fuel substrate may provide a possibility for the novel therapeutic approach to the treatment of cerebral ischemia.
 ...
PMID:Pyruvate ameliorates post ischemic injury of rat astrocytes and protects them against PARP mediated cell death. 1460 78

As diverse pruritic cutaneous diseases respond to ultraviolet treatment, we have examined whether ultraviolet light is capable of inducing apoptosis in mast cells. Human mast cell line 1 (HMC1) derived from a patient with malignant mastocytosis and purified skin mast cells were irradiated with single doses of ultraviolet B or ultraviolet A1, or pretreated with 8-methoxypsoralen prior to ultraviolet A1 exposure. After 0 to 48 h of incubation, the percentage of apoptotic and dead cells was assessed. In HMC1 cells, morphologic features of apoptosis were further evaluated by electron microscopy. All ultraviolet treatment induced apoptosis of HMC1 cells in a time- and dose-dependent manner. Apoptosis was associated with activation of caspase-3, release of cytochrome C, cleavage of poly(ADP-ribose)-polymerase, and nuclear accumulation of p53. In contrast, resting skin mast cells were resistant to ultraviolet light induced apoptosis. After incubation with stem cell factor and interleukin-4 for 2 wk, however, slowly proliferating skin mast cells also underwent apoptosis in response to ultraviolet light. In conclusion, these data demonstrate that ultraviolet light directly affects mast cells, but mainly aims at the proliferating mast cells as found in mastocytosis and mast cell dependent pruritic diseases, where increased numbers are observed due to the recruitment mast cell precursors from the blood.
 ...
PMID:Ultraviolet irradiation induces apoptosis in human immature, but not in skin mast cells. 1463 3

The aim of the therapy of human malignancies is the inhibition of cell proliferation and/or induction of apoptosis. We studied the kinetics of the morphological and biochemical changes in HeLa cells during chemotherapy by cisplatin (CP). Apoptosis was evaluated by scoring of cells exhibiting changes characteristic for early and late stages of apoptosis as determined by Hoechst 33258 staining and by examination of positive reaction for activated caspase-3. Expression and intracellular localization of distinct proteins was analyzed by immunoblotting of subcellular fractions and segregation of nucleoli by immunocytochemistry. Chromatin fragmentation characteristic for apoptosis was observed in single cells after 3h cisplatin. A strong cytoplasmic accumulation of cytochrome C detected by immunoblotting 6h post-treatment was accompanied by an activation of caspase-9. Neither inhibition of cell division nor blocking of DNA replication preceded the onset of apoptosis. Our results show that after short treatment by CP, cell proliferation and apoptosis concomitantly occurred.
 ...
PMID:Induction of cell cycle arrest and apoptosis in human cervix carcinoma cells during therapy by cisplatin. 1464 57

Cerebellar Purkinje neurons (PNs) are selectively vulnerable to AMPA (alpha-amino-3-hydroxy-5-methyl-4-isoxazolepriopionic acid)-induced delayed neurotoxicity known as dark cell degeneration (DCD) that is expressed as cytoplasmic and nuclear condensation, neuron shrinkage, and failure of physiology. The present study was initiated to determine whether AMPA-receptor-induced DCD in PNs is associated with Bax translocation to the mitochondria, cytochrome C release from the mitochondria, changes in mitochondrial potential, and activation of representative initiator and executor caspases that include caspase-9, caspase-3, and caspase-7. AMPA consistently and rapidly hyperpolarized mitochondria as reflected by an increase in MitoTracker Red CMS Ros fluorescence. Increases in Bax immunoreactivity were quantitatively and temporally variable and Bax failed to localize to mitochondria. Additionally, we observed a marked increase in immunoreactivity of cytochrome C although its release from mitochondria was not apparent. Mitochondrial membrane hyperpolarization and increases in cytochrome C immunoreactivity preceded caspase activation. Immunohistochemical analyses revealed the active form of caspases-3 and -9 were markedly and significantly increased in PNs following 30 microM AMPA, and caspase-9 activation preceded caspase-3. Increases in active caspase-7 immunoreactivity were less frequently encountered in PNs. Thus DCD shares some characteristics of apoptotic programmed cell death, but lacks typical mitochondrial pathophysiology associated with classic apoptosis. These findings suggest that AMPA-induced DCD is a form of active PCD that lies on a spectrum between classical apoptosis and passive necrosis.
 ...
PMID:AMPA-induced dark cell degeneration of cerebellar Purkinje neurons involves activation of caspases and apparent mitochondrial dysfunction. 1464 40

In this study we determined whether caspase-3 is required in mouse cortical neurons for sodium azide-mediated apoptosis. Primary cortical neuronal cultures were treated with a cell permeable caspase-3 inhibitor, DEVD (1 nM-100 fM), prior to sodium azide-induced hypoxia. Treatment with the caspase-3 inhibitor resulted in a dose-dependent decrease in apoptosis, suggesting that sodium azide-induced apoptosis is mediated through a caspase-3 dependent pathway. Levels of cytochrome-c release and caspase-3 cleavage were assayed by Western analysis. Cytochrome-c release and caspase-3 cleavage were observed at 5 h (85.3+/-5.8%) and 8 h (53.4+/-14.9%), respectively. We have previously reported that angiotensin II, acting through the AT(2) receptor subtype, protects cultured mouse cortical neurons from sodium azide-induced apoptosis. We also examined whether the protective effect of angiotensin II is mediated through modulation of caspase-3. Pre-treatment of cells with angiotensin II and the AT(1) receptor antagonist, losartan, reduced levels of sodium azide-induced caspase-3 cleavage by 95.0+/-4.0%. Cells pre-treated with the AT(2) receptor antagonist, PD123319 showed a smaller reduction of caspase-3 cleavage (53.8+/-3.4%). Our findings indicate that sodium azide-induced apoptosis is caspase-3 dependent and that angiotensin II protects cortical neurons from chemical-induced apoptosis by reducing caspase-3 cleavage.
 ...
PMID:Angiotensin II attenuates chemical hypoxia-induced caspase-3 activation in primary cortical neuronal cultures. 1470 44

We have examined mitochondrial membranes and molecular hallmarks of apoptosis in response to increasing concentrations of 1-Methyl, 4-phenyl, Pyridinium ion (MPP(+)) in SK-N-SH neurons and have evaluated the neuroprotective potential of Selegiline with a primary objective to explore its mechanism(s) of neuroprotection. MPP(+)-induced apoptosis was characterized by spherical appearance, suppressed neuritogenesis, phosphatidyl serine externalization, plasma membrane perforations, mitochondrial membrane potential (Delta Psi) collapse, mitochondrial aggregation, and nuclear DNA fragmentation and condensation. At lower concentrations, MPP(+) (10-100 microM) produced mitochondrial swelling and loss of cristae, and at higher concentrations (300-500 microM), degeneration and aggregation of mitochondrial membranes in the peri-nuclear region, which were attenuated by Selegiline (10-50 microM) pre-treatment. At still higher concentrations, MPP(+) (>500 microM) produced necrotic changes represented by mitochondrial and plasma membrane ballooning and perforations. Selegiline provided partial neuroprotection at higher concentrations of MPP(+). MPP(+)-induced increases in reactive oxygen species, lipid peroxidation, cytochrome-C release, necrosis factor kappa-B (NF-kappa-B) activation, 8-hydroxy, 2 deoxy guanosine synthesis, alpha-synuclein indices, and reductions in glutathione, ATP, and superoxide dismutase were attenuated by Selegiline. Selegiline also attenuated MPP(+)-induced transcriptional activation of c-fos, c-jun, GAPDH, and caspase-3, suggesting that it may provide neuroprotection by preserving mitochondrial membranes, by attenuating molecular markers of apoptosis, by scavenging free radicals, and by regulating immediate early genes involved in neurodegeneration.
 ...
PMID:Neuroprotective actions of Selegiline in inhibiting 1-methyl, 4-phenyl, pyridinium ion (MPP+)-induced apoptosis in SK-N-SH neurons. 1472 76

Aldehydes are ubiquitous pollutants with well-indicated but ill-defined cardiovascular toxicity. To investigate the direct toxic effects of environmental aldehyde exposure on the myocardium, 8-wk-old male ICR (Institute of Cancer Research) strain mice were gavage fed trans-2-hexenal (0.1, 1, 10, or 50 mg/kg/wk) or corn oil (vehicle) for 4 wk, during which cardiac function, myocardial morphology, cardiomyocyte apoptosis, and the cytochrome cmediated caspase activation apoptotic pathway were determined. Quantification by enzyme-linked immunosorbent assay (ELISA) revealed that aldehyde- protein adducts increase in mouse hearts following hexenal treatment, whereas echocardiographic analysis displayed a significant impairment of basal left-ventricular contractile function. Both histological analysis and TUNEL (terminal deoxynucleotidyl transferase-mediated nick-end labeling) staining indicated condensed nuclei and a significant increase in cardiomyocyte apoptosis in these mice, but immunohistochemistry-based confocal microscope revealed no marked myofibril disarray. Release of cytochrome c from mitochondria into the cytosol, concomitant with activation of caspase-3 and -9, was also found in hexenal-treated groups. In addition, isolated cardiac mitochondria formed hexenal-protein adducts when treated with hexenal, providing indirect evidence that the cardiac mitochondrion is one of primary subcellular targets of aldehyde toxins. These findings suggest that trans-2-hexenal exposure results in direct cardiac toxicity through, at least in part, induction of mitochondrial cytochrome c release-mediated apoptosis in cardiomyocytes, indicating that the cardiac mitochondrion is one of principal subcellular targets of aldehyde toxins.
 ...
PMID:Cardiac toxic effects of trans-2-hexenal are mediated by induction of cardiomyocyte apoptotic pathways. 1473 31


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>