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)

Neuronal apoptotic execution uses a cytochrome c-dependent caspase activation mechanism that is conserved in other cell types. Phosphatidylinositol 3-kinase and its downstream effector, Akt/protein kinase B, appear to control this mechanism and govern the life/death decision. We have developed a cell-free system using cytosol from human neuroblastoma (SY5Y) cells that reconstitutes biochemical features of neuronal apoptosis. In the presence of cytochrome c and ATP, caspase-9 and -3 were activated, which initiated chromatin condensation and DNA cleavage in rat pheochromocytoma (PC12) nuclei. Akt was cleaved in reactions where caspase-3 was activated and its cleavage was prevented by the caspase inhibitor DEVD-aldehyde. The phosphatase inhibitors orthovanadate and okadaic acid prevented catalytic processing and activation of caspase-3 and digestion of Akt and partially inhibited cleavage of caspase-9. Caspase-dependent destruction of Akt irreversibly inactivates this key mediator of survival signaling, ensuring that the execution pathway will prevail.
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PMID:Phosphorylation-dependent Akt cleavage in neural cell in vitro reconstitution of apoptosis. 1050 Dec 28

Neuronal necrosis and apoptosis occur after traumatic brain injury (TBI) in animals and contribute to subsequent neurological deficits. In contrast, relatively little apoptosis is found after mechanical injury in vitro. Because in vivo trauma models and clinical head injury have associated cerebral ischemia and/or metabolic impairment, we transiently impaired cellular metabolism after mechanical trauma of neuronal-glial cultures by combining 3-nitropropionic acid treatment with concurrent glucose deprivation. This produced greater neuronal cell death than mechanical trauma alone. Such injury was attenuated by the NMDA receptor antagonist dizocilpine (MK801). In addition, this injury significantly increased the number of apoptotic cells over that accruing from mechanical injury alone. This apoptotic cell death was accompanied by DNA fragmentation, attenuated by cycloheximide, and associated with an increase in caspase-3-like but not caspase-1-like activity. Cell death was reduced by the pan-caspase inhibitor BAF or the caspase-3 selective inhibitor z-DEVD-fmk, whereas the caspase-1 selective inhibitor z-YVAD-fmk had no effect; z-DEVD-fmk also reduced the number of apoptotic cells after combined injury. Moreover, cotreatment with MK801 and BAF resulted in greater neuroprotection than either drug alone. Thus, in vitro trauma with concurrent metabolic inhibition parallels in vivo TBI, showing both NMDA-sensitive necrosis and caspase-3-dependent apoptosis.
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PMID:Combined mechanical trauma and metabolic impairment in vitro induces NMDA receptor-dependent neuronal cell death and caspase-3-dependent apoptosis. 1050 92

Since caspase members have been identified as effectors of apoptosis, the role of CPP32/caspase-3 was further explored in cultured neurons from the embryonic rat forebrain submitted to a 6-h hypoxia which has previously been shown to induce apoptotic death within four days after reoxygenation, whereas a shorter aggression (i.e., for 3 h) leads by the same time to an increased number of living neurons, suggesting that sublethal hypoxia may promote neurogenesis. Neuronal expression of the active cleavage product of CPP32 (CPP32 p20) increased specifically after hypoxia for 6 h to finally reach 985% over control normoxic values at 96 h post-insult, while a 3-h hypoxia triggered the inducible stress protein HSP70 that has been shown to inhibit caspase-3. Proteolytic activity of caspase-3 was progressively stimulated by lethal hypoxia, as reflected by the degradation of two selective substrates, including poly (ADP-ribose) polymerase (PARP). Caspase-3 activity was blocked specifically and dose-dependently by the peptide inhibitor, DEVD-CHO, that reduced the number of apoptotic cells and prevented the hypoxia-induced decrease in cell viability, including when given 24 h post-insult. Interestingly, in these conditions, the inhibitory compounds enhanced the number of mitotic neurons. These data emphasize the critical role of caspase-3 in neuronal injury consecutive to hypoxia. Whereas caspase inhibitors may provide benefit over a broad therapeutic window, they might allow developing neurons to complete their cell cycle initiated in response to stress, as it is the case for sublethal hypoxia.
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PMID:CPP32/CASPASE-3-like proteases in hypoxia-induced apoptosis in developing brain neurons. 1052 77

Midkine (MK) is a new member of the heparin-binding neurotrophic factor family. MK plays important roles in development and carcinogenesis and has several important biological effects, including promotion of neurite extension and neuronal survival. However, the mechanism by which MK exerts its neurotrophic actions on neurons has not been elucidated to date. We have established an apoptosis induction system by serum deprivation in primary neuronal cultures isolated from mouse cerebral cortices. Neuronal apoptosis induced by serum deprivation was accompanied by the activation of caspase-3. MK, when added into the culture medium, inhibited the induction of apoptosis and activation of caspase-3 in a dose-dependent manner. Extracellular signal-regulated kinase (ERK) and Akt were not activated by serum deprivation, whereas ERK and Akt were rapidly activated by addition of MK. In addition, the trophic actions of MK of suppressing apoptosis and suppressing the activation of caspase-3 were abolished by concomitant treatment with PD98059, a specific inhibitor of mitogen-activated protein kinase kinase, and with wort-mannin or LY294002, specific inhibitors of phosphatidyl-inositol 3-kinase (PI 3-kinase). These PI 3-kinase inhibitors also inhibited the activation of ERK in response to MK, demonstrating a link between ERK and the caspase-3 pathway that is modulated by the PI 3-kinase activation. These results indicate that the ERK cascade plays a central role in MK-mediated neuronal survival via inhibition of caspase-3 activation.
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PMID:Midkine inhibits caspase-dependent apoptosis via the activation of mitogen-activated protein kinase and phosphatidylinositol 3-kinase in cultured neurons. 1053 68

Neuronal loss is prominent in Alzheimer's disease (AD), and its mechanisms remain unresolved. Apoptotic cell death has been implicated on the basis of studies demonstrating DNA fragmentation and an up-regulation of proapoptotic proteins in the AD brain. However, DNA fragmentation in neurons is too frequent to account for the continuous neuronal loss in a degenerative disease extending over many years. Furthermore, the typical apoptotic morphology has not been convincingly documented in AD neurons with fragmented DNA. We report the detection of the activated form of caspase-3, the central effector enzyme of the apoptotic cascade, in AD and Down's syndrome (DS) brain using an affinity-purified antiserum. In AD and DS, single neurons with apoptotic morphology showed cytoplasmic immunoreactivity for activated caspase-3, whereas no neurons were labeled in age-matched controls. Apoptotic neurons were identified at an approximate frequency of 1 in 1100 to 5000 neurons in the cases examined. Furthermore, caspase-3 immunoreactivity was detected in granules of granulovacuolar degeneration. Our results provide direct evidence for apoptotic neuronal death in AD with a frequency compatible with the progression of neuronal degeneration in this chronic disease and identify autophagic vacuoles of granulovacuolar degeneration as possible means for the protective segregation of early apoptotic alterations in the neuronal cytoplasm.
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PMID:Activation of caspase-3 in single neurons and autophagic granules of granulovacuolar degeneration in Alzheimer's disease. Evidence for apoptotic cell death. 1055 Mar 1

The mechanism of neuronal death in brain ischaemia remains unclear. Morphology, terminal transferase-mediated dUTP-digoxigenin nick end-labelling (TUNEL) and immunohistochemistry for the pro-apoptotic enzyme caspase-3 (CASP3), for its substrates poly(ADP-ribose) polymerase (PARP) and the DNA-dependent protein kinase catalytic subunit (DNA-PKCS) and for poly(ADP-ribose) (PAR), an end-product of PARP activity, were used to investigate neuronal death in brain infarcts from 15 men and 20 women, aged 46-95 years. The infarcts varied in age from 18 h to several months. Neuronal death was characterized morphologically by cell shrinkage, cytoplasmic hypereosinophilia and moderate nuclear pyknosis with later chromatin dispersal and disintegration, but not features of apoptosis. Occasional apoptotic bodies were seen but these appeared to be related to inflammatory cells, endothelial cells and occasional glia, including satellite cells. Neurones within infarcts showed strong nuclear and cytoplasmic labelling for CASP3 during the first 2 days after infarction. Neuronal DNA-PKCS, PARP and poly(ADP-ribose) immunoreactivity was demonstrable in scattered neurones in and adjacent to infarcts for 18-24 h but thereafter declined to below detectable levels in most cases. TUNEL labelled cells towards the edge of the infarcts, particularly at 2-4 days, but most of the labelling could be prevented by preincubation of the sections in diethyl pyrocarbonate to inactivate endogenous nucleases. Between 3 days and 3 weeks, CASP3 and DNA-PKCS were detected in proliferating capillaries and CASP3, PARP and poly(ADP-ribose) in infiltrating macrophages. Our findings indicate that neuronal death in human brain infarcts has some of the early biochemical features of programmed cell death, with upregulation of CASP3 and rapid disappearance of DNA-PKCS and PARP. However, the morphological changes are not those of apoptosis, the DNA cleavage occurs relatively late, and some of the TUNEL is probably mediated by the release of endogenous endonucleases during protease or microwave pretreatment of the damaged tissue.
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PMID:Neuronal death in brain infarcts in man. 1073 67

Although apoptotic pathways play important roles in ischemic neuronal injury, exact mechanism of apoptotic enzyme cascade has not been fully studied. Immunohistochemical stainings for cytochrome c and caspase-3, and histochemical staining for a terminal deoxynucleotidyl-transferase (TdT)-mediated dUTP-biotin nick end-labeling method (TUNEL) were examined in a rat model of permanent middle cerebral artery (MCA) occlusion. Cytochrome c was strongly induced in neurons of the ischemic penumbra from 3 h after MCA occlusion, and caspase-3 began to be induced in the same area from 3 h with a peak at 8 h. Neuronal cells in MCA area became TUNEL positive at delayed time, reaching a peak at 24 h. Thus, the peak of induction of cytochrome c preceded that of caspase-3, and these two peaks were also precedence of the peak of DNA-fragmentation. Western blot analysis showed cytosolic expression of cytochrome c from mitochondria. This study demonstrated 1. Rapid release of cytochrome c from mitochondria to the cytosol, mainly in neurons of the cortex at 3 h after ischemia. 2. Subsequent peaks of caspase-3 and TUNEL in this order. These temporal profiles suggest a serial cascadic activation of apoptotic pathways in neuronal death after permanent MCA occlusion of rats.
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PMID:Temporal profile of cytochrome c and caspase-3 immunoreactivities and TUNEL staining after permanent middle cerebral artery occlusion in rats. 1076 14

Neuronal cell death is an essential feature of nervous system development and neurodegenerative diseases. Most Purkinje cells in murine cerebellar organotypic culture die when taken from 1-5-day-old mice (P1-P5), whereas they survive when taken before or after these ages. Using DNA gel electrophoresis, terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling (TUNEL) and electron microscopic analyses, we were able to show that this massive Purkinje cell death is apoptotic in nature and reaches a peak at P3. From the several endogenous genes known to be involved in the apoptotic process, we have focused on two: the bcl-2 and the caspase-3 that encode for anti-apoptotic and pro-apoptotic proteins, respectively. Immunostaining for activated Caspase-3 correlated with Purkinje cell death. A better survival of Purkinje cells was observed in P3 slices taken from hu-bcl-2 transgenic mice, and in slices treated with z-DEVD.fmk (an inhibitor of numerous caspases). Thus, these two genes are implicated in the age-related Purkinje cell apoptosis in organotypic culture. As Purkinje cell death in vitro takes place at the same age as Purkinje cells engaged in intense synaptogenesis and dendritic remodeling in vivo, we propose that this apoptosis reflects a naturally occurring Purkinje cell death during this critical period.
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PMID:Implication of Bcl-2 and Caspase-3 in age-related Purkinje cell death in murine organotypic culture: an in vitro model to study apoptosis. 1097 35

Neuronal injury may be dependent upon the generation of the free radical nitric oxide (NO) and the subsequent induction of programmed cell death (PCD). Although the nature of this injury may be both preventable and reversible, the underlying mechanisms that mediate PCD are not well understood. Using the agent nicotinamide as an investigative tool in primary rat hippocampal neurons, the authors examined the ability to modulate two independent components of PCD, namely the degradation of genomic DNA and the early exposure of membrane phosphatidylserine (PS) residues. Neuronal injury was determined through trypan blue dye exclusion, DNA fragmentation, externalization of membrane PS residues, cysteine protease activation, and the measurement of intracellular pH (pHi). Exposure to the NO donors SIN-1 and NOC-9 (300 micromol/L) alone rapidly increased genomic DNA fragmentation from 20 +/- 4% to 71 +/- 5% and membrane PS exposure from 14 +/- 3% to 76 +/- 9% over a 24-hour period. Administration of a neuroprotective concentration of nicotinamide (12.5 mmol/L) consistently maintained DNA integrity and prevented the progression of membrane PS exposure. Posttreatment paradigms with nicotinamide at 2, 4, and 6 hours after NO exposure further demonstrated the ability of this agent to prevent and reverse neuronal PCD. Although not dependent upon pHi, neuroprotection by nicotinamide was linked to the modulation of two independent components of neuronal PCD through the regulation of caspase 1 and caspase 3-like activities and the DNA repair enzyme poly(ADP-ribose) polymerase. The current work lays the foundation for the development of therapeutic strategies that may not only prevent the course of PCD, but may also offer the ability for the repair of neurons that have been identified through the loss of membrane asymmetry for subsequent destruction.
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PMID:Prevention of nitric oxide-induced neuronal injury through the modulation of independent pathways of programmed cell death. 1099 60

Neuronal survival during the developmental period of naturally occurring cell death is mediated through a successful competition for limiting concentrations of neurotrophic factors, and the deprived neurons will die. New results show that induced death through the p75 neurotrophin receptor (p75(NTR)), a member of the p55TNF/Fas family of cell death receptors, may also influence survival during development. We find that eliminating p75(NTR) or neurotrophin 4 (NT4) in mice leads to a marked attenuation of apoptosis during the programmed cell death period of the trigeminal ganglion neurons, suggesting that NT4 can induce the death of these neurons through the p75(NTR). These in vivo findings were reproduced in primary cell cultures, where NT4 was found to induce death in a p75(NTR)-dependent pathway. Analysis of p75 deficient and wild-type cells revealed two separate cell death pathways, a p75(NTR)- and caspase-3-independent pathway activated by trophic factor deprivation, and a p75(NTR)- and caspase-3-dependent pathway initiated by NT4. Crossing in the NT4 null alleles in brain-derived neurotrophic factor (BDNF) null mutant mice led to a rescue of a large proportion of BDNF-dependent neurons from excessive cell death, indicating that trophic factor deprivation is not sufficient for the death of many neurons and that additional death inducing signals might be required. Our results suggest that NT4 competitively signals survival and death of sensory neurons through trkB and p75(NTR), respectively.
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PMID:Attenuation of a caspase-3 dependent cell death in NT4- and p75-deficient embryonic sensory neurons. 1099 52


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