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Query: UNIPROT:P42574 (
caspase-3
)
45,978
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
An essential role for caspases in programmed neuronal cell death has been demonstrated in various in vitro studies, and synthetic caspase inhibitors have recently been shown to prevent neuronal cell loss in animal models of focal cerebral ischemia and traumatic brain injury, respectively. The therapeutic utility of caspase inhibitors, however, will depend on preservation of both structural and functional integrity of neurons under stressful conditions. The present study demonstrates that expression and proteolytic activity of
caspase-3
is up-regulated in the rat hippocampus after transient forebrain ischemia. Continuous i.c.v. infusion of the caspase inhibitor N-benzyloxycarbonyl-Asp(OMe)-Glu(OMe)-Val-Asp(OMe)-fluoromethyl ketone significantly attenuated
caspase-3
-like enzymatic activity, and blocked delayed cell loss of hippocampal
CA1
neurons after ischemia. Administration of N-benzyloxycarbonyl-Asp(OMe)-Glu(OMe)-Val-Asp(OMe)-fluoromethyl ketone, however, did not prevent impairment of induction of long-term potentiation in post-ischemic
CA1
cells, suggesting that caspase inhibition alone does not preserve neuronal functional plasticity.
...
PMID:Inhibition of caspases prevents cell death of hippocampal CA1 neurons, but not impairment of hippocampal long-term potentiation following global ischemia. 1050 44
Release of cytochrome c (cyt c) into cytoplasm initiates caspase-mediated apoptosis, whereas activation of Akt kinase by phosphorylation at serine-473 prevents apoptosis in several cell systems. To investigate cell death and cell survival pathways, the authors studied release of cyt c, activation of caspase, and changes in Akt phosphorylation in rat brains subjected to 15 minutes of ischemia followed by varying periods of reperfusion. The authors found by electron microscopic study that a portion of mitochondria was swollen and structurally altered, whereas the cell membrane and nuclei were intact in hippocampal
CA1
neurons after 36 hours of reperfusion. In some neurons, the pattern of immunostaining for cyt c changed from a punctuate pattern, likely representing mitochondria, to a more diffuse cytoplasmic localization at 36 and 48 hours of reperfusion as examined by laser-scanning confocal microscopic study. Western blot analysis showed that cyt c was increased in the cytosolic fraction in the hippocampus after 36 and 48 hours of reperfusion. Consistently,
caspase-3
-like activity was increased in these hippocampal samples. As demonstrated by Western blot using phosphospecific Akt antibody, phosphorylation of Akt at serine-473 in the hippocampal region was highly increased during the first 24 hours but not at 48 hours of reperfusion. The authors conclude that transient cerebral ischemia activates both cell death and cell survival pathways after ischemia. The activation of Akt during the first 24 hours conceivably may be one of the factors responsible for the delay in neuronal death after global ischemia.
...
PMID:Survival- and death-promoting events after transient cerebral ischemia: phosphorylation of Akt, release of cytochrome C and Activation of caspase-like proteases. 1053 37
The ubiquitin-proteasome protein degradation pathway is crucial in controlling intracellular levels of a variety of short-lived proteins and maintaining cellular growth and metabolism. In a previous study, we showed the accumulation of conjugated ubiquitin in
CA1
neurons of the gerbil after 5 min of forebrain ischemia (; ). The accumulation of conjugated ubiquitin may reflect proteasome malfunction. In the present study, we investigated the effects of proteasome inhibitors on primary neuronal cultures to determine whether proteasomal malfunction induces neuronal death. When carbobenzoxy-Leu-Leu-Leu-aldehyde or lactacystin, two different types of proteasome inhibitors, were separately used to suppress proteasome activity, we observed induction of apoptotic neuronal cell death in both cases. During the apoptotic process, mitochondrial membrane potential was disrupted, cytochrome-c was released from mitochondria into the cytosol, and
caspase-3
-like proteases were activated. Apoptosis was inhibited by pretreatment with acetyl-aspartyl-glutamyl-valyl-aspart-1-aldehyde or overexpression of Bcl-x/(L). These results demonstrated that suppression of proteasome function induces neuronal apoptosis via the release of cytochrome c from mitochondria and activation of
caspase-3
-like proteases.
...
PMID:Proteasome inhibitors induce cytochrome c-caspase-3-like protease-mediated apoptosis in cultured cortical neurons. 1062 3
Neuroprotective effects of a Group II metabotropic glutamate receptor agonist, LY379268, were examined in a neonatal rat model of hypoxia-ischemia (unilateral common carotid artery ligation followed by hypoxic exposure for 1.5h in 7-day-old rat pups). LY379268 administered 5 min after hypoxic exposure (2, 5, or 10 mg/kg, i.p.) significantly reduced brain injury as measured by reductions in the ipsilateral brain weight and in
CA1
hippocampal neuron density. The significant neuroprotective effects were also observed when this compound (5 mg/kg) was administered 30 min, but not 60 min, after hypoxic exposure. The neonatal hypoxia-ischemia (HI) procedure significantly increased
caspase-3
activity and induced DNA fragmentation in the ipsilateral cortex compared with that in the contralateral cortex 24 and 72h after the insult, respectively. LY379268 did not prevent this increase in
caspase-3
activity and DNA fragmentation in the ipsilateral cortex. These results suggest that activation of Group II metabotropic glutamate receptors may provide neuroprotection against HI brain injury. However, blockade of
caspase-3
activation and the apoptotic pathway appears not to be involved in the neuroprotective effects of LY379268 observed in the neonatal rat model of HI.
...
PMID:Protection of neonatal rat brain from hypoxic-ischemic injury by LY379268, a Group II metabotropic glutamate receptor agonist. 1071 35
Accumulating evidence strongly suggests that apoptosis contributes to neuronal cell death in a variety of neurodegenerative contexts. Activation of the cysteine protease
caspase-3
appears to be a key event in the execution of apoptosis in the central nervous system (CNS). As a result, mice null for
caspase-3
display considerable neuronal expansion usually resulting in death by the second week of life. At present, 14 caspase family members have been identified and subdivided into three subgroups on the basis of preference for specific tetrapeptide motifs using a positional scanning combinatorial substrate library.
Caspase-3
is a group II member (2, 3, 7) categorized by an absolute substrate requirement for aspartic acid in the P4 position of the scissile bond. The preferred cleavage motif (DExD) for group II caspases is found in many structural, metabolic and repair proteins essential for cellular homeostasis. Consistent with the proposal that apoptosis plays a central in role human neurodegenerative disease,
caspase-3
activation has recently been observed in stroke, spinal cord trauma, head injury and Alzheimer's disease. Indeed, peptide-based caspase inhibitors prevent neuronal loss in animal models of head injury and stroke suggesting that these compounds may be the forerunners of non-peptide small molecules that halt apoptosis processes implicated in these neurodegenerative disorders. A clear link between an hereditary neurodegenerative disorder and failed caspase inhibition has recently been proposed for spinal muscular atrophy (SMA). In severe SMA, the neuronal specific inhibitor of apoptosis (IAP) family member known as NAIP is often dysfunctional due to missense and truncation mutations. IAPs such as NAIP potently block the enzymatic activity of group II caspases (3 and 7) suggesting that NAIP mutations may permit unopposed developmental apoptosis to occur in sensory and motor systems resulting in lethal muscular atrophy. Conversely, adenovirally-mediated overexpression of NAIP or the X-linked IAP called XIAP reduces the loss of
CA1
hippocampal neurons following transient forebrain ischemia. Taken together, these findings suggest that anti-apoptotic strategies may some day have utility in the treatment of neurodegenerative disease. The present review will summarize some of the recent evidence suggesting that apoptosis inhibitors may become a practical therapeutic approach for both acute and chronic neurodegenerative conditions.
...
PMID:Neuroprotection by the inhibition of apoptosis. 1076 48
We examined the cytochrome c oxidase (COX) activity in gerbil hippocampal
CA1
neurons after 5-min ischemia by a histochemical method in the presence or absence of exogenous cytochrome c. In the
CA1
neurons, COX activity without exogenous cytochrome c decreased from 1 h after ischemia, but was restored by the addition of exogenous cytochrome c in the following 6 h after ischemia. These results suggest that it is not COX activity but endogenous cytochrome c that is changed in the early phase after ischemia, and that COX activity begins to decrease 9 h after ischemia. We examined
caspase-3
in the
CA1
region by immunoblotting, as
caspase-3
is known to take part in the cell-death cascade downstream from cytochrome c. Although pro-
caspase-3
was strongly detected, active
caspase-3
was not detected before and until 84 h after 5-min ischemia. Our data suggested that delayed neuronal death is likely to progress via cytochrome c-release but not via
caspase-3
activation.
...
PMID:Histochemical cytochrome c oxidase activity and caspase-3 in gerbil hippocampal CA1 neurons after transient forebrain ischemia. 1079 43
Hirano bodies are eosinophilic rod-like inclusions that are found predominantly in neuronal processes in the hippocampal
CA1
sector with increasing age and are particularly numerous in Alzheimer's disease. They contain a variety of cytoskeletal epitopes, especially actin and actin-binding proteins. Actin cleavage by cysteinyl aspartate-specific proteases (caspases) is a feature of apoptosis. Cleavage at aspartate 244 generates N-terminal 32 kDa and C-terminal 15 kDa actin fragments. This has led to the development of a rabbit polyclonal antibody specific for caspase-cleaved actin, directed to the last five C-terminal amino acids of the 32 kDa fragment of actin ('fractin'). Fractin immunohistochemistry was performed on hippocampal sections from Alzheimer's disease and control cases containing numerous Hirano bodies, in addition to immunolabelling with CM1 antiserum which recognizes activated
caspase-3
. The Hirano bodies showed strong diffuse fractin immunoreactivity. They did not label with CM1 antiserum, perhaps reflecting too low a level of activated
caspase-3
for immunodetection, or involvement of a different member of the caspase family. The finding of fractin immunoreactivity of Hirano bodies suggests that caspase-like cleavage of actin may play a role in their formation and further supports caspase-like activity in neuronal processes, distinct from that associated with acute perikaryal apoptosis.
...
PMID:Caspase-cleaved actin (fractin) immunolabelling of Hirano bodies. 1093 67
The temporospatial expression pattern of the nuclear DNA repair enzyme redox factor-1 (ref-1), the p53-activated gene (pag) 608 and the effector
caspase-3
was examined by in situ hybridization histochemistry in gerbils subjected to two 10-min episodes of unilateral common carotid artery occlusion, separated by 5h. Gene responses were correlated with the metabolic state, as revealed by regional adenosine 5'-triphosphate bioluminescent imaging, and with the degree of histological damage, as assessed by haematoxylin-eosin staining and terminal deoxynucleotidyl transferase-mediated-dUTP nick end labeling (TUNEL), in order to evaluate the role of these genes in the maturation of injury. Focal infarcts developed in the dorsolateral cerebral cortex at the bregma level and the nucleus caudate-putamen within four days after repeated unilateral ischemia, as indicated by a secondary adenosine 5'-triphosphate loss after initial adenosine 5'-triphosphate recovery and by histomorphological signs of pannecrosis. The more caudal cortex at hippocampal levels and the hippocampus (CA1>CA3 area), however, exhibited selective neuronal injury without adenosine 5'-triphosphate depletion. TUNEL+ cells appeared starting 5h after repeated unilateral ischemia. TUNEL+ cells reached maximum levels in the caudate-putamen at 12-24h, but much later in the cortex and hippocampus at two days after ischemia. Remarkably few TUNEL+ cells were noticed in the thalamus, where adenosine 5'-triphosphate state did not recover after reperfusion. Following repeated unilateral ischemia, a transient elevation of ref-1 mRNA was detected after 5h in the cerebral cortex and hippocampal
CA1
area. Ref-1 mRNA levels decreased within 12-24h, before the onset of tissue damage. Subsequently, pag608 and
caspase-3
mRNA levels increased, closely in parallel with the appearance of DNA fragmented cells, but slightly prior to the deterioration of adenosine 5'-triphosphate state. In the caudate-putamen, pag608 and
caspase-3
mRNAs reached maximum levels already 12-24h after repeated common carotid artery occlusion, when DNA fragmentation was most prominent, and declined thereafter. In the cortex and hippocampal
CA1
-3 areas, where DNA damage appeared more slowly, pag608 and
caspase-3
mRNAs were induced starting 24h after ischemia, and remained elevated even after two to four days. The levels of pag608 and
caspase-3
mRNAs were similar at rostral and caudal levels of the cortex, as well as in the hippocampal
CA1
and CA3 area, although the degree of injury differed considerably between these structures. Notably, pag608 and
caspase-3
mRNAs were not elevated in the thalamus after repeated unilateral ischemia. The present report shows a close temporal association between the induction of ref-1, pag608 and
caspase-3
mRNAs, the manifestation of cell injury and the secondary adenosine 5'-triphosphate depletion in infarcting brain areas, suggesting (i) that de novo responses of these genes may be involved in the maturation of cell injury and (ii) that apoptotic programs and the secondary deterioration of cerebral energy state may interfere with each other after ischemia.
...
PMID:Expression of redox factor-1, p53-activated gene 608 and caspase-3 messenger RNAs following repeated unilateral common carotid artery occlusion in gerbils--relationship to delayed cell injury and secondary failure of energy state. 1118 42
To determine whether apoptotic process is involved in the delayed neuronal death in hippocampal
CA1
region following forebrain ischemia in gerbils, time dependent activation of caspase and DNA fragmentation were evaluated by immuno-staining and terminal dUTP nick-end-labeling staining, respectively. After transient forebrain ischemia in gerbils, activation of apoptosis related caspase, including
caspase-3
, was apparent, and it preceded DNA fragmentation in
CA1
region. These observations suggest that apoptotic process is involved in hippocampal delayed neuronal death.
...
PMID:Caspase activation as an apoptotic evidence in the gerbil hippocampal CA1 pyramidal cells following transient forebrain ischemia. 1120 85
In a rat forebrain ischemia model, the authors examined whether loss of cytochrome c from mitochondria correlates with ischemic hippocampal
CA1
neuronal death and how cytochrome c release may shape neuronal death. Forebrain ischemia was induced by bilateral common carotid artery occlusion with simultaneous hypotension for 10 minutes. After reperfusion, an early rapid depletion of mitochondrial cytochrome c and a late phase of diffuse redistribution of cytochrome c occurred in the hippocampal
CA1
region, but not in the dentate gyrus and CA3 regions. Intracerebroventricular administration of Z-DEVD-FMK, a relatively selective
caspase-3
inhibitor, provided limited but significant protection against ischemic neuronal damage on day 7 after reperfusion. Treatment with 3 minutes of ischemia (ischemic preconditioning) 48 hours before the 10-minute ischemia attenuated both the early and late phases of cytochrome c redistribution. In another subset of animals treated with cycloheximide, a general protein synthesis inhibitor, the late phase of cytochrome c redistribution was inhibited, whereas most hippocampal
CA1
neurons never regained mitochondrial cytochrome c. Examination of neuronal survival revealed that ischemic preconditioning prevents, whereas cycloheximide only delays, ischemic hippocampal
CA1
neuronal death. DNA fragmentation detected by terminal deoxytransferase-mediated dUTP-nick end labeling (TUNEL) in situ was largely attenuated by ischemic preconditioning and moderately reduced by cycloheximide. These results indicate that the loss of cytochrome c from mitochondria correlates with hippocampal
CA1
neuronal death after transient cerebral ischemia in relation to both caspase-dependent and -independent pathways. The amount of mitochondrial cytochrome c regained may determine whether ischemic hippocampal
CA1
neurons survive or succumb to late-phase death.
...
PMID:Both caspase-dependent and caspase-independent pathways may be involved in hippocampal CA1 neuronal death because of loss of cytochrome c From mitochondria in a rat forebrain ischemia model. 1133 63
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