EC:3.4.22.56 - FACTA Search

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

In this study, we investigated the involvement of caspases in TGFbeta-induced apoptosis in human B cells. Our results show that TGFbeta-mediated nuclear fragmentation, observed in the Epstein-Barr virus-negative Burkitt's Lymphoma cell line BL41, was abolished in the presence of the tripeptide caspase inhibitor zVAD-fmk or the specific caspase-3 inhibitor DEVD-fmk. Other apoptotic manifestations such as cell shrinkage, surface phosphatidylserine expression and chromatin condensation were strongly inhibited by zVAD-fmk but only partially by DEVD-fmk. This suggests that other caspases in addition to caspase-3 control these apoptotis-associated features. Specific activation of caspase-3 during TGFbeta-induced apoptosis was demonstrated by the DEVD-fmk-sensitive expression of the active p17 subunit of caspase-3 and by in vivo cleavage of PARP. In addition, TGFbeta treatment of BL41 promoted the expression of both dephosphorylated and truncated forms of the retinoblastoma protein. Inhibition of caspase-3 activity abolished both nuclear fragmentation and expression of the truncated retinoblastoma protein, without modifying the G1 cell cycle arrest induced by TGFbeta. Our data thus demonstrate that TGFbeta-induced apoptosis of lymphoma B lymphocytes is dependent on caspase activation and involves caspase-dependent cleavage of the retinoblastoma protein.
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PMID:Role of caspases and possible involvement of retinoblastoma protein during TGFbeta-mediated apoptosis of human B lymphocytes. 1037 29

Programmed cell death has been proposed to play a role in the death of neurons in acute and chronic degenerative neurologic disease. There is now evidence that the caspases, a family of cysteine proteases, mediate programmed cell death in various cells. In neurons, caspase-3 (CPP32/Yama/apopain), in particular, has been proposed to play a role. We examined the expression of caspase-3 in three models of programmed cell death affecting neurons of the substantia nigra in the rat: natural developmental neuron death and induced developmental death following either striatal target injury with quinolinic acid or dopamine terminal lesion with intrastriatal injection of 6-hydroxydopamine. Using an antibody to the large (p17) subunit of activated caspase-3, we have found that activated enzyme is expressed in apoptotic profiles in all models. Increased p17 immunostaining correlated with increased enzyme activity. The subcellular distribution of activated caspase-3 differed among the models: In natural cell death and the target injury model, it was strictly nuclear, whereas in the toxin model, it was also cytoplasmic. We conclude that p17 immunostaining is a useful marker for programmed cell death in neurons of the substantia nigra.
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PMID:Activation of caspase-3 in developmental models of programmed cell death in neurons of the substantia nigra. 1038 85

Caspases are a family of cysteine proteases activated during apoptosis. Modification of caspases by nitric oxide and its relevance during apoptosis is currently a controversial subject. In this study we analyzed the S-nitrosated form of caspase-3 at a molecular level. By using electrospray ionization-mass spectrometry, we detected poly-S-nitrosation of caspase-3 with an average of about 2 molecules of NO bound per enzyme. Although NO treatment completely inhibited enzyme activity, S-nitrosation was not restricted to the active site cysteine. Rather, we detected multiple relative mass increases of 30 +/- 1 Da in both the p12 and p17 subunits of caspase-3, corresponding to single to triple S-nitrosation. The stability of these S-nitrosations differed in physiologically relevant concentrations of 5 mM glutathione. Whereas all S-nitroso bonds in the p12 subunit were cleaved with release of NO and partial formation of protein-mixed disulfides with glutathione, a single S-nitrosation in the p17 subunit remained stable. Since this S-nitrosation was not observed in a mutant form of caspase-3 lacking the active site cysteine, we conclude that NO nitrosates the active site cysteine of caspase-3 and that this modification is notably inert to fast trans-nitrosation with glutathione. Furthermore, we provide evidence that treatment of caspase-3 with NO can lead to mixed disulfide formation with glutathione, demonstrating the oxidative character of NO.
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PMID:Mass spectrometric analysis of nitric oxide-modified caspase-3. 1040 38

Caspases and Bcl-xL, the mammalian homologues of the Caenorhabditis elegans (C. elegans) ced-3 and ced-9 genes, respectively, regulate apoptosis of various cells. Caspase-3 is processed into an active form (p20 or p17 and p12) during apoptosis. We investigated the relation between caspase-3 and Bcl-xL during development by examining activation of caspase-3 and apoptotic cells in Bcl-x-deficient (bcl-x(-/-)) mice at embryonic (E) day 11.5. We used a double-staining technique with a cleavage site-directed antibody against caspase-3 (anti-p20/17) and terminal-deoxytransferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL). Bcl-xL-deficiency increased both numbers of p20/17-positive and -negative apoptotic cells in dorsal root ganglia (DRG); the numbers of p20/17-positive apoptotic cells in the caudal parts of the ventral hindbrain and ventral spinal cord; and the numbers of p20/17-negative apoptotic cells in the dorsal midbrain, dorsal hindbrain, and dorsal spinal cord. Thus, Bcl-xL blocks the caspase-3-dependent apoptotic pathway in the restricted regions of the nervous system during development. Furthermore, these observations suggest that Bcl-xL protects against activation of the caspase-3-independent apoptotic pathway. Other caspases or apoptotic mechanisms may also be activated in the nervous systems of bcl-x(-/-) mice.
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PMID:Bcl-xL is a negative regulator of caspase-3 activation in immature neurons during development. 1044 48

The mechanism of apoptosis induced by 2-chloro-2'-deoxyadenosine (2CdA) in human leukemia cell line MOLT-4 was investigated. 2CdA induced increases of 3'-OH ends of genomic DNA, ladder-like DNA fragmentation and phosphatidylserine translocation to the outer membrane, which are apoptotic characteristics. These apoptotic phenomena induced by 2CdA were inhibited by cycloheximide (CHX; a protein synthesis inhibitor), deoxycytidine (dC; a substrate of deoxycytidine kinase), acetyl Ile-Glu-Thr-Asp aldehyde (Ac-IETD-CHO; a caspase-8 inhibitor) and acetyl Asp-Glu-Val-Asp aldehyde (Ac-DEVD-CHO; a caspase-3 inhibitor). The protein synthesis-dependent expression of Fas and Fas ligand (Fas-L) was detected by treatment with 2CdA. The proteolytic processing of procaspases-8 and -3 to produce active fragments, caspases-8 (p18) and -3 (p17), respectively, was observed after treatment with 2CdA, and suppressed by cycloheximide. Increases in the activities of caspases-8 and -3 were observed after 2CdA treatment. Their activation was also dependent on protein synthesis. These results indicated that 2CdA-induced apoptosis was triggered by phosphorylation of 2CdA followed by the protein synthesis-dependent expression of Fas and Fas-L and activation of caspases-8 and -3.
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PMID:2-Chloro-2'-deoxyadenosine induces apoptosis through the Fas/Fas ligand pathway in human leukemia cell line MOLT-4. 1067 48

In the aftermath of prolonged continuous seizure activity (status epilepticus, SE), neuronal cell death occurs in the brain regions through which the seizure propagates. Recent studies have implicated apoptotic processes in this seizure-related injury. Because activation of caspase-3-like cysteine proteases plays a crucial role in mammalian neuronal apoptosis, we explored the possibility that activation of caspase-3 is involved in the neuronal apoptotic cell death that occurs in rat brain following SE induced by systemic kainic acid. Caspase-3 activity was determined immunocytochemically using CM1 antibodies specific for catalytically active subunit (p17) of the enzyme. We found an induction of caspase-3 activity in rhinal cortex and amygdala at 24 h after SE. To determine whether activation of caspase-3-like proteases is a necessary component of the injury process, we delivered a caspase-3 inhibitor, z-DEVD-fmk, into the lateral ventricle prior to, and following SE. z-DEVD-fmk treatment substantially attenuated apoptotic cell death after SE, both in hippocampus and rhinal cortex, as evaluated by analysis of internucleosomal DNA fragmentation and neuronal nuclear morphology. Our findings implicate caspase-3 cysteine protease in the neurodegenerative response to SE and suggest that this degeneration can be attenuated by inhibition of caspase-3-like enzyme activity.
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PMID:Intracerebral injection of caspase-3 inhibitor prevents neuronal apoptosis after kainic acid-evoked status epilepticus. 1068 42

The induction of cell death in leukemic HL-60 cells by the ether lipid 1-O-octadecyl-2-O-methyl-rac-glycero-3-phosphocholine (ET-18-OCH(3); edelfosine) followed the typical apoptotic changes in ultrastructural morphology, including blebbing, chromatin condensation, nuclear membrane breakdown and extensive vacuolation. Using a cytofluorimetric approach, we found that ET-18-OCH(3) induced disruption of the mitochondrial transmembrane potential (DeltaPsi(m)) followed by production of reactive oxygen species (ROS) and DNA fragmentation in leukemic cells. ET-18-OCH(3) also induced caspase-3 activation in human leukemic cells, as assessed by cleavage of caspase-3 into the p17 active form and cleavage of the caspase-3 substrate poly(ADP-ribose) polymerase (PARP). ET-18-OCH(3) analogues unable to induce apoptosis failed to disrupt DeltaPsi(m) and to activate caspase-3. ET-18-OCH(3)-resistant Jurkat cells generated from sensitive Jurkat cells showed no caspase-3 activation and did not undergo DeltaPsi(m) disruption upon ET-18-OCH(3) incubation. Cyclosporin A partially inhibited DeltaPsi(m) dissipation, caspase activation and apoptosis in ET-18-OCH(3)-treated leukemic cells. Overexpression of bcl-2 by gene transfer prevented DeltaPsi(m) collapse, ROS generation, caspase activation and apoptosis in ET-18-OCH(3)-treated leukemic T cells. Pretreatment with the caspase inhibitor Z-Asp-2, 6-dichlorobenzoyloxymethylketone prevented ET-18-OCH(3)-induced PARP proteolysis and DNA fragmentation, but not DeltaPsi(m) dissipation. ET-18-OCH(3) did not affect the expression of caspases and bcl-2-related genes. ET-18-OCH(3)-induced apoptosis did not require protein synthesis. Our data indicate that DeltaPsi(m) dissipation and caspase-3 activation are critical events of the apoptotic cascade triggered by the antitumor ether lipid ET-18-OCH(3), and that the sequence of events in the apoptotic action of ET-18-OCH(3) on human leukemic cells is: DeltaPsi(m) disruption, caspase-3 activation and internucleosomal DNA degradation.
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PMID:Involvement of mitochondria and caspase-3 in ET-18-OCH(3)-induced apoptosis of human leukemic cells. 1073 48

In this study, we examined the susceptibility of murine hepatoma Hepa1-6 cells to undergo IFN-gamma- and/or TNF-alpha-induced apoptosis. IFN-gamma or TNF-alpha alone had no demonstrable cytotoxic effects, whereas IFN-gamma and TNF-alpha in combination induced apoptosis drastically in Hepa1-6 cells. During this apoptosis, an increase in caspase-3- and -8-like protease activities and activation of caspase-3, identified by the appearance of its p17 fragment, were observed. Moreover, the cytotoxic induction and caspase-3 activation were effectively inhibited by Z-Asp-CH(2)-DCB (Z-Asp), a caspase inhibitor. Further, an elevation of cytochrome c in the cytosol, in a parallel to activation of caspase-3, was observed in a time-dependent manner. Concurrently, up-regulation of caspase-11 gene expression and processing of procaspase-11 were detected during this apoptosis. These results suggest that the caspase-3 activation, the release of cytochrome c from mitochondria, and increased caspase-11 gene expression involve in synergistic induction of apoptosis in Hepa1-6 cells by IFN-gamma and TNF-alpha.
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PMID:Synergistic induction of apoptosis in murine hepatoma Hepa1-6 cells by IFN-gamma and TNF-alpha. 1086 Aug 13

Nuclear morphological changes during apoptosis are very distinct and effector caspases have been implicated to play a central role in these processes. To investigate this in greater detail we examined the effect of blocking caspase activity and its activation on the nuclear morphological change in Jurkat T cells undergoing apoptosis after staurosporine treatment. In the presence of caspase inhibitors, like benzyloxycarbonyl-Val-Ala-Asp fluoro-methylketone (z-VAD-FMK), N-acetyl Tyr-Val-Ala-Asp chloromethylketone (Ac-YVAD-CMK) and benzyloxy-carbonyl-Asp-Glu-Val-Asp (OMe) fluoromethylketone (z-DEVD-FMK), staurosporine-treated Jurkat cells displayed a nuclear morphological change distinct from that of normal and apoptotic cells. This nuclear morphological change is an early event, characterised by convoluted nuclei with cavitations, and clumps of chromatin abutting to inner regions of the nuclear envelope between the nuclear pores. Both the nuclear envelope and endoplasmic reticulum were grossly dilated. This pre-apoptotic nuclear change precedes the externalisation of phosphatidylserine, chromatin condensation and DNA laddering, and can be dissociated from the formation of high molecular weight DNA fragments and cell shrinkage. Although cytochrome c efflux from the mitochondria and the processing of caspase-3 were observed in Jurkat cells with pre-apoptotic nuclear morphology, caspase-2, -6, -7 and -8 were not activated. In the presence of z-DEVD-FMK or Ac-YVAD-CMK, caspase-3 was processed to both the p17 and p20 fragments in staurosporine-treated cells, but only to p20 fragment in the presence of z-VAD-FMK. However, the caspase-3 substrate, poly(ADP ribose) polymerase was not cleaved in the presence of z-VAD-FMK, despite >70% of the cells have pre-apoptotic nuclei. In addition, caspase-3 null MCF-7 cells also undergo pre-apoptotic nuclear change when treated with staurosporine in the presence of caspase inhibitors, indicating that caspase-3 is not required for the early nuclear morphological change in cells undergoing apoptosis. Although cell death in staurosporine-treated Jurkat cells was markedly delayed, they eventually die without discernible downstream apoptotic features. Other apoptotic stimuli like etoposide and the heavy metal chelator, N,N,N',N'-tetrakis (2-pyridylmethyl) ethylenediamine also induced this nuclear morphological change in Jurkat cells in the presence of z-VAD-FMK. In summary, the effector caspases are not involved in early nuclear morphological change, which precedes the conventional hallmark morphological changes associated with chemical-induced apoptosis.
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PMID:Effector caspases are dispensable for the early nuclear morphological changes during chemical-induced apoptosis. 1093 34

Birth asphyxia can cause moderate to severe brain injury. It is unclear to what degree apoptotic or necrotic mechanisms of cell death account for damage after neonatal hypoxia-ischemia (HI). In a 7-d-old rat HI model, we determined the contributions of apoptosis and necrosis to neuronal injury in adjacent Nissl-stained, hematoxylin and eosin-stained, and terminal deoxynucleotidyl transferase-mediated UTP nick end-labeled sections. We found an apoptotic-necrotic continuum in the morphology of injured neurons in all regions examined. Eosinophilic necrotic neurons, typical in adult models, were rarely observed in neonatal HI. Electron microscopic analysis showed "classic" apoptotic and necrotic neurons and "hybrid" cells with intermediate characteristics. The time course of apoptotic injury varied regionally. In CA3, dentate gyrus, medial habenula, and laterodorsal thalamus, the density of apoptotic cells was highest at 24-72 hr after HI and then declined. In contrast, densities remained elevated from 12 hr to 7 d after HI in most cortical areas and in the basal ganglia. Temporal and regional patterns of neuronal death were compared with expression of caspase-3, a cysteine protease involved in the execution phase of apoptosis. Immunocytochemical and Western blot analyses showed increased caspase-3 expression in damaged hemispheres 24 hr to 7 d after HI. A p17 peptide fragment, which results from the proteolytic activation of the caspase-3 precursor, was detected in hippocampus, thalamus, and striatum but not in cerebral cortex. The continued expression of activated caspase-3 and the persistence of cells with an apoptotic morphology for days after HI suggests a prolonged role for apoptosis in neonatal hypoxic ischemic brain injury.
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PMID:Apoptosis has a prolonged role in the neurodegeneration after hypoxic ischemia in the newborn rat. 1105 Jan 20

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