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Query: UNIPROT:P42574 (
caspase-3
)
45,978
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
We analyzed a set of 103 non-small cell lung carcinomas (NSCLCs) for
caspase-3
, -6 and -8 expression and apoptosis. Additionally, the expression of bcl-2, bax and p53 were studied.
Caspase-3
positivity appeared as diffuse, cytoplasmic staining and was restricted to the tumor area. In contrast, the immunoreactivity for
caspase-6
was intense, granular and mostly located in single cells or groups of tumor cells showing apoptotic morphology. The caspase-8 expression pattern was a combination of the two other caspases studied, featuring both diffuse and single-cell patterns restricted to the tumor area. No significant differences were seen in caspase -3, -6 and -8 expression between tumors of different histological types or grades. The number of apoptotic cells and bodies was significantly higher in NSCLCs, in which caspase-8 immunostaining was mainly seen in single cells (p = 0.017), whereas caspase -3 and -6 expression had no association with apoptosis. It is apparent that, in lung tissue, up-regulation of caspase expression is a phenomenon associated solely with neoplasia and reflects the readiness of the tumor cells to undergo apoptosis. Interestingly, caspases -3, -6 and -8 each have an individual staining pattern in NSCLC, perhaps reflecting their different position in the caspase hierarchy.
...
PMID:Expression of caspases-3, -6 and -8 and their relation to apoptosis in non-small cell lung carcinoma. 1141 Aug 65
The aim of this study is to elucidate the possible mechanism of apoptosis in response to hypoxia in MC3T3E1 osteoblasts. MC3T3E1 osteoblasts under hypoxic conditions (2% oxygen) resulted in apoptosis in a time-dependent manner estimated by DNA fragmentation assay and nuclear morphologystained with fluorescent dye, Hoechst 33258. Pretreatment with Z-VAD-FMK, a pan-caspase inhibitor, or Z-DEVD-CHO, a specific
caspase-3
inhibitor, completely suppressed the DNA ladder in response to hypoxia. An increase in
caspase-3
-like protease (DEVDase) activity was observed during apoptosis, but no caspase- activity (YVADase) was detected. To confirm what caspases are involved in apoptosis, western blot analysis was performed using anti-
caspase-3
or -6 antibody. The 10-kDa protein, corresponding to the active products of
caspase-3
and the 10-kDA protein of the active protein of
caspase-6
were generated in hypoxia-challenged cells in which processing of the full length form of
caspase-3
and -6 was evident. With a time course similar to this
caspase-3
and -6 activation was evident, hypoxic stress caused the cleavage of lamin A, typical of
caspase-6
activity. In addition, the stress elicited the release of cytochrome c into the cytosol during apoptosis. Furthermore, we have observed that pre-treatment with SB203580, a selective p38 MAP kinase (p38 MAPK) inhibitor, attenuated the hypoxia-induced apoptosis. The addition of SB203580 suppressed
caspase-3
and -6-like protease activity by hypoxia up to 50%. In contrast, PD98059 had no effect on the hypoxia-induced apoptosis. To confirm the involvement of MAP kinase, JNK/SAPK, ERK, or p38 kinase assay was performed. Although p38 MAPK was activated in response to hypoxic treatment, the other MAP kinase -JNK/SAPK or ERK- was not or modestly activated. These results suggest that p38 MAPK positively regulates hypoxia-induced apoptosis in MC3T3E1 osteoblasts.
...
PMID:Hypoxia induces apoptosis by caspase activation accompanying cytochrome C release from mitochondria in MC3T3E1 osteoblasts. p38 MAPK is related in hypoxia-induced apoptosis. 1141 43
Photodynamic therapy (PDT) is under investigation for the treatment of intimal hyperplastia in conditions such as atherosclerosis and restenosis. Although smooth muscle cells (SMCs) may be a key target for treatment, the effects of PDT on these cells are poorly characterized. In the present study, apoptosis was induced in primary human aortic SMCs by the combination of the photosensitizer verteporfin and visible light. After PDT, an increase in mitochondrial cytochrome c (cyt c) and apoptosis-inducing factor (AIF) levels were detected in the cytosol immediately and their levels increased steadily up to 2 hours. Cytosolic levels of the pro-apoptotic Bcl-2 family member Bax decreased reciprocally throughout this period, but this change did not occur before cyt c release. Confocal microscopy revealed a diffuse staining pattern of cyt c within apoptotic cells as compared to a distinct mitochondrial staining in normal cells. AIF translocated from mitochondria to the nucleus during the progression of apoptosis. After cyt c release, caspase-9 and
caspase-3
processing was visible by 1 hour and
caspase-6
, -7, and -8 processing was apparent by 2 hours after PDT. In summary, these results demonstrate for the first time the cellular redistribution of mitochondrial AIF during SMC apoptosis, as well as the early release of cyt c and the subsequent activation of multiple caspases during PDT-induced SMC apoptosis.
...
PMID:Mitochondrial release of apoptosis-inducing factor and cytochrome c during smooth muscle cell apoptosis. 1143 77
Endoplasmic reticulum (ER) stress elicits protective responses of chaperone induction and translational suppression and, when unimpeded, leads to caspase-mediated apoptosis. Alzheimer's disease-linked mutations in presenilin-1 (PS-1) reportedly impair ER stress-mediated protective responses and enhance vulnerability to degeneration. We used cleavage site-specific antibodies to characterize the cysteine protease activation responses of primary mouse cortical neurons to ER stress and evaluate the influence of a PS-1 knock-in mutation on these and other stress responses. Two different ER stressors lead to processing of the ER-resident protease procaspase-12, activation of calpain,
caspase-3
, and
caspase-6
, and degradation of ER and non-ER protein substrates. Immunocytochemical localization of activated
caspase-3
and a cleaved substrate of
caspase-6
confirms that caspase activation extends into the cytosol and nucleus. ER stress-induced proteolysis is unchanged in cortical neurons derived from the PS-1 P264L knock-in mouse. Furthermore, the PS-1 genotype does not influence stress-induced increases in chaperones Grp78/BiP and Grp94 or apoptotic neurodegeneration. A similar lack of effect of the PS-1 P264L mutation on the activation of caspases and induction of chaperones is observed in fibroblasts. Finally, the PS-1 knock-in mutation does not alter activation of the protein kinase PKR-like ER kinase (PERK), a trigger for stress-induced translational suppression. These data demonstrate that ER stress in cortical neurons leads to activation of several cysteine proteases within diverse neuronal compartments and indicate that Alzheimer's disease-linked PS-1 mutations do not invariably alter the proteolytic, chaperone induction, translational suppression, and apoptotic responses to ER stress.
...
PMID:Endoplasmic reticulum stress-induced cysteine protease activation in cortical neurons: effect of an Alzheimer's disease-linked presenilin-1 knock-in mutation. 1157 34
We have shown previously that
caspase-6
activity is lethal to human neurons (LeBlanc et al., 1999; Zhang et al., 2000). Here we find that 17-beta-estradiol but not 17-alpha-estradiol prevents
caspase-6
-mediated neuronal cell death. 17-beta-estradiol-treated neuronal extracts directly inhibit recombinant active
caspase-6
,
caspase-3
, caspase-7, and caspase-8 in vitro. We conclude that 17-beta-estradiol induces a caspase inhibitory factor (CIF) that is preventing neuronal apoptosis. The induction of CIF occurs within 10 min of 17-beta-estradiol exposure to neurons, does not require de novo protein synthesis, and involves mitogen-activated protein kinase activation. The effect is antagonized by the estrogen receptor antagonist tamoxifen. In contrast, 17-beta-estradiol does not induce CIF or prevent caspase-mediated cell death in cultured astrocytes. CIF does not act through oxidation of the caspase active site. CIF activity copurifies with proteins of between 12 and 14 kDa in size. Our results indicate that 17-beta-estradiol induces an inhibitor of active caspases through a receptor-mediated nongenomic pathway and provide an additional mechanism for the neuroprotective action of 17-beta-estradiol that is likely highly relevant to the understanding of the role of estrogen against Alzheimer's disease.
...
PMID:17-beta-estradiol induces an inhibitor of active caspases. 1158 6
Apoptosis is mainly brought about by the activation of caspases, a protease family with unique substrate selectivity. In mammals, different complexes like the DISC complex or the apoptosome complexes have been delineated leading to the cleavage and thus activation of the executioner caspases. Although
caspase-3
is the main executioner caspase in apoptosis induced by serum starvation in AKR-2B fibroblasts as demonstrated by affinity labeling with YVK(-bio)D.aomk and partial purification of cytosolic extracts by high performance ion exchange chromatography, its activation is apparently caused by a noncanonical pathway: (1) Expression of CrmA, an inhibitor of caspase-8, failed to suppress apoptosis; (2) There was no formation of high molecular weight complexes of Apaf-1 indicative for its activation. Furthermore no cleavage of caspase-9 was observed. But surprisingly, gelfiltration experiments revealed the distribution of
caspase-3
and -6 into differently sized high molecular weight complexes during apoptosis. Though the apparent molecular weights of the complexes containing
caspase-3
(600 kD for apoptosome and 250 kD for microapoptosome) are in accordance with recently published data, the activity profiles differ strikingly. In AKR-2B cells
caspase-3
is mainly recovered as uncomplexed enzyme and in much lower levels in the apoptosomes. Remarkably, the 600 kD and 250 kD complexes containing activated
caspase-3
were devoid of Apaf-1 and cytochrome c. In addition a new 450 kD complex containing activated
caspase-6
was found that is clearly separated from the
caspase-3
containing complexes. Furthermore, we disclose for the first time the activation of caspase-12 in response to serum starvation. Activated caspase-12 is detectable as non-complexed free enzyme in the cytosol.
...
PMID:Formation of noncanonical high molecular weight caspase-3 and -6 complexes and activation of caspase-12 during serum starvation induced apoptosis in AKR-2B mouse fibroblasts. 1184 Jan 63
The role of protein kinase C-beta(II) (PKC-beta(II)) in etoposide (VP-16)-induced apoptosis was studied using polyomavirus-transformed pyF111 rat fibroblasts in which PKC-beta(II) specific activity in the nuclear membrane (NM) doubled and the enzyme was cleaved into catalytic fragments. No PKC-beta(II) complexes with lamin B1 and/or active caspases were immunoprecipitable from the NM of proliferating untreated cells, but large complexes of PKC-beta(II) holoprotein and its catalytic fragments with lamin B1, active
caspase-3
and -6, and inactive phospho-CDK-1, but not PKC-beta(I) or PKC-delta, could be immunoprecipitated from the NM of VP-16-treated cells, suggesting that PKC-beta(II) is an apoptotic lamin kinase. By 30 min after normal nuclei were mixed with cytoplasms from VP-16-treated, but not untreated, cells, PKC-beta(II) holoprotein had moved from the apoptotic cytoplasm to the normal NM, and lamin B1 was phosphorylated before cleavage by
caspase-6
. Lamin B1 phosphorylation was partly reduced, but its cleavage was completely prevented, despite the presence of active
caspase-6
, by adding a selective PKC-betas inhibitor, hispidin, to the apoptotic cytoplasms. Thus, a PKC-beta(II) response to VP-16 seems necessary for lamin B1 cleavage by
caspase-6
and nuclear lamina dissolution in apoptosing pyF111 fibroblasts. The possibility of PKC-beta(II) being an apoptotic lamin kinase in these cells was further suggested by lamin B1-bound PKC-delta being inactive or only slightly active and by PKC-alpha not combining with the lamin.
...
PMID:Protein kinase C-beta II Is an apoptotic lamin kinase in polyomavirus-transformed, etoposide-treated pyF111 rat fibroblasts. 1190 Nov 53
Glutamate and the NO donor, nitroprusside, synergistically induced the death of B50 cells from a rat CNS-derived neuroblastoma cell line. With low [nitroprusside] (10 microM) both nitroprusside and glutamate were required. Under these conditions, nuclei became pyknotic and caspases were activated. The activities of
caspase-3
and
caspase-6
(effector caspases) were higher than those of caspase-8 and caspase-9 (initiator caspases). The activation of all four caspases was inhibited by cyclosporin A, with the order of susceptibility caspase-8=caspase-9=caspase-6>
caspase-3
. To identify the possible locus of cyclosporin A action, we used an antisense oligodeoxynucleotide to suppress the level of cyclophilin-A to<5% of its control value. Cyclophilin-A suppression largely reproduced the inhibitory effects of cyclosporin A. These results provide the first indication that cyclophilin-A participates in the activation of the caspase cascade in neuronal cells, in particular in the form of cascade elicited by excitotoxic stimuli. It is concluded that neuroprotection by cyclosporin A against excitotoxin-induced apoptosis is, at least partly, due to inhibition of cyclophilin-A.
...
PMID:Cyclophilin-A is involved in excitotoxin-induced caspase activation in rat neuronal B50 cells. 1190 43
The activation of the extracellular signal-regulated kinases (ERKs) by tumour necrosis factor-alpha (TNF) receptors (TNFRs) is an integral part of the cytokine's pleiotropic cellular responses. Here we report differences in the caspase sensitivity and TNFR subtype activation of members of the ERK family. Inhibition in HeLa cells of caspase function by pharmacological inhibitors or the expression of CrmA (cytokine response modifier A), a viral modifier protein, blocks TNF-induced apoptosis or caspase-dependent protein kinase Cdelta and poly(ADP-ribose) polymerase protein degradation. TNFR1- or TNFR2-stimulated c-Jun N-terminal kinase (JNK) activity was attenuated in cells in which caspase activity was inhibited either by pharmacological blockers or CrmA expression. Both TNFR1- and TNFR2-stimulated JNK activity was caspase-sensitive; however, only TNFR1 was capable of stimulating p42/44 mitogen-activated protein kinase (MAPK) and p38 MAPK activities. TNFR1-stimulated p42/44 MAPK and p38 MAPK activities were insensitive to pharmacological caspase inhibition or CrmA. These findings were supported when measuring TNF-induced cytosolic phospholipase A(2) activation, which is a downstream target for MAPK and p38 MAPK. Profiling caspase enzymes activated by TNF in HeLa cells showed sequential caspase-8, -3, -7, -6 and -9 activation, with their inhibition characteristics suggesting a role for
caspase-3
and/or
caspase-6
in modulating JNK activity. Taken together these results show delineated ERK-activation pathways employed by TNFR subtypes.
...
PMID:Tumour necrosis factor-induced activation of c-Jun N-terminal kinase is sensitive to caspase-dependent modulation while activation of mitogen-activated protein kinase (MAPK) or p38 MAPK is not. 1199 67
Estrogen plays a critical role in the protection from apoptosis in several cell types because the withdrawal of estrogen leads to increased apoptosis in tissues such as the brain, endothelium, testes, and uterus. Our recent report demonstrated that the chick oviduct also regresses through apoptotic mechanisms during estrogen deficiency. Despite these observations, very little is known concerning the intracellular mechanisms by which estrogen opposes apoptosis. To better understand how estrogen exerts its antiapoptotic effects, several key apoptotic genes were examined for their regulation by estrogen. Our results show that mRNA expression levels of Bcl-2, hsp-70, c-myc, Bcl-X(l),
caspase-3
, and
caspase-6
remain essentially constant when apoptosis is stimulated by estrogen withdrawal. However, the genes for caspase-1 and caspase-2 are rapidly stimulated, at least for the most part, at the transcriptional level after the withdrawal of estrogen. This increase in caspase-2 mRNA is followed by an increase in enzyme activity. Furthermore, although mRNA expression levels are unaffected, both
caspase-3
and
caspase-6
proenzymes are activated in the estrogen-withdrawn cells. Taken together, these results demonstrate that estrogen has the potential to oppose apoptosis by regulating caspase activity through both transcriptional and posttranscriptional mechanisms in reproductive tissues.
...
PMID:Tissue-protective effects of estrogen involve regulation of caspase gene expression. 1204 18
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