Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P42574 (caspase-3)
 45,978 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Nitric oxide (NO) induction through the inducible NO synthase has been demonstrated to cause cell death in macrophages. We demonstrate that, in macrophages that have been rendered resistant to apoptosis induced by inducible NO synthase (RES cells), exposure to exogenous NO donors results in a hypersensitive apoptosis reaction when compared with the parental RAW 264.7 cells. The apoptosis induced via exogenous NO donors was found to be caspase 3-independent. Although caspase 3 activity was stimulated in the apoptotic macrophages, inhibition of caspase 3 by the inhibitor DEVD-CHO (N-acetyl-Asp-Glu-Val-Asp-aldehyde) did not reverse the apoptosis induced by the NO donor S-nitrosoglutathione (GSNO). This suggests that although caspase 3 activity is stimulated during apoptosis in macrophages, this signal is not sufficient to induce apoptosis. Cleavage of the enzyme poly(ADP ribose) polymerase mirrors our results of the caspase activity. Interestingly, we show that exogenous NO donation results in an accumulation of cells at the G2/M-phase border. Here, we demonstrate that the mitogen activated protein kinase kinase (MEK) inhibitor PD 098059 can be used to reverse the G2/M-phase block and show that this treatment also inhibits the observed apoptosis in RES macrophages. Treatment with the MEK inhibitor also reversed both the caspase 3 activity and poly(ADP ribose) polymerase cleavage in cells treated with GSNO. This result indicates that the mitogen-activated protein kinase pathway may be involved in regulation of the caspase cascade. Alternatively, it may suggest an activity for the MEK inhibitor heretofore not observed, that of a cyclin kinase inhibitor. Our results suggest that selection of macrophages by resistance to endogenously generated NO may cause hypersensitivity to exogenous NO donors. These findings have relevant implications for the treatment of apoptotic-resistant cell populations that may occur in both cancer and atheroma.
 ...
PMID:Macrophages resistant to endogenously generated nitric oxide-mediated apoptosis are hypersensitive to exogenously added nitric oxide donors: dichotomous apoptotic response independent of caspase 3 and reversal by the mitogen-activated protein kinase kinase (MEK) inhibitor PD 098059. 956 Feb 25

Physiological cell deaths occur ubiquitously throughout biology and have common attributes, including apoptotic morphology with mitosis-like chromatin condensation and prelytic genome digestion. The fundamental question is whether a common mechanism of dying underlies these common hallmarks of death. Here we describe evidence of such a conserved mechanism in different cells induced by distinct stimuli to undergo physiological cell death. Our genetic and quantitative biochemical analyses of T- and B-cell deaths reveal a conserved pattern of requisite components. We have dissected the role of cysteine proteases (caspases) in cell death to reflect two obligate classes of cytoplasmic activities functioning in an amplifying cascade, with upstream interleukin-1beta-converting enzyme-like proteases activating downstream caspase 3-like caspases. Bcl-2 spares cells from death by punctuating this cascade, preventing the activation of downstream caspases while leaving upstream activity undisturbed. This observation permits an operational definition of the stages of the cell death process. Upstream steps, which are necessary but not themselves lethal, are modulators of the death process. Downstream steps are effectors of, and not dissociable from, actual death; the irreversible commitment to cell death reflects the initiation of this downstream phase. In addition to caspase 3-like proteases, the effector phase of death involves the activation in the nucleus of cell cycle kinases of the cyclin-dependent kinase (Cdk) family. Nuclear recruitment and activation of Cdk components is dependent on the caspase cascade, suggesting that catastrophic Cdk activity may be the actual effector of cell death. The conservation of the cell death mechanism is not reflected in the molecular identity of its individual components, however. For example, we have detected different cyclin-Cdk pairs in different instances of cell death. The ordered course of events that we have observed in distinct cases reflects essential thematic elements of a conserved sequence of modulatory and effector activities comprising a common pathway of physiological cell death.
 ...
PMID:Commitment and effector phases of the physiological cell death pathway elucidated with respect to Bcl-2 caspase, and cyclin-dependent kinase activities. 956 10

The activation of cyclin-dependent kinases (cdks) has been implicated in apoptosis induced by various stimuli. We find that the Fas-induced activation of cdc2 and cdk2 in Jurkat cells is not dependent on protein synthesis, which is shut down very early during apoptosis before caspase-3 activation. Instead, activation of these kinases seems to result from both a rapid cleavage of Wee1 (an inhibitory kinase of cdc2 and cdk2) and inactivation of anaphase-promoting complex (the specific system for cyclin degradation), in which CDC27 homolog is cleaved during apoptosis. Both Wee1 and CDC27 are shown to be substrates of the caspase-3-like protease. Although cdk activities are elevated during Fas-induced apoptosis in Jurkat cells, general activation of the mitotic processes does not occur. Our results do not support the idea that apoptosis is simply an aberrant mitosis but, instead, suggest that a subset of mitotic mechanisms plays an important role in apoptosis through elevated cdk activities.
 ...
PMID:Caspase-dependent activation of cyclin-dependent kinases during Fas-induced apoptosis in Jurkat cells. 961 90

We report here that p21WAF1/CIP1, an inhibitor of cyclin kinases, underwent proteolytic processing into a smaller fragment, p14, in the early stage of apoptosis in SK-HEP-1 cells. Apoptosis was induced by either staurosporine or ginsenoside Rh2, a ginseng saponin with a dammarane skeleton. Proteolytic processing was the result of caspase-3 activity, which accompanied the early changes in cell morphology and DNA fragmentation. p21WAF1/CIP1 translated in vitro was cleaved into a p14 fragment when incubated with cell extracts obtained from either ginsenoside Rh2-treated or staurosporine-treated cells. Cleavage was equally inhibited in both cases by adding Ac-DEVD-CHO, a specific caspase-3 inhibitor, but not by Ac-YVAD-CHO, a specific caspase-1 inhibitor. Similarly, p21WAF1/CIP1 was efficiently cleaved by recombinant caspase-3, overexpressed in Escherichia coli. Moreover, the endogenous p21WAF1/CIP1 of untreated cell extracts was also cleaved by recombinant caspase 3, as measured by immunoblotting. Mutation analysis allowed identification of two caspase-3 cleavage sites, DHVD112/L and SMTD149/F, which are located within or near the interaction domains for cyclins, Cdks, and proliferating cell nuclear antigen (PCNA). Taken together, these results show that ginsenoside Rh2 and staurosporine increase caspase-3 activity, which in turn directly cleaves p21WAF1/CIP1 during the early stages of apoptosis. We propose that proteolytic cleavage of p21WAF1/CIP1 is a functionally relevant event that allows release of the cyclin/Cdk complex from the p21WAF1/CIP1 inhibitor, resulting in the elevated levels of cyclin/Cdk kinase activity seen in the earlier stage of apoptosis.
 ...
PMID:Caspase 3 specifically cleaves p21WAF1/CIP1 in the earlier stage of apoptosis in SK-HEP-1 human hepatoma cells. 979 25

p27[KIP1] (p27) is a cyclin dependent kinase inhibitor, involved in the negative regulation of G1 progression in response to a number of anti-proliferative signals. In this study we show, in growing mouse hybridoma (7TD1) and human myeloma (U266) cell lines, that p27 is highly expressed but slightly upregulated when cells are arrested, regardless to the phases of the cell cycle. In contrast, the specific blockade of these cells in early G1 phase reveals the induction of a protein of 23 kDa (p23) specifically recognized by polyclonal anti-p27 antibodies raised against the NH2 terminal part of p27 but not by anti-p21[CIP1] antibodies. Experiments using caspase inhibitors strongly suggest that p23 results from the proteolysis of p27 by a 'caspase-3-like' protease. This cleavage leads to the cytosolic sequestration of p23 but does not alter its binding properties to CDK2 and CDK4 kinases. Indeed, p23 associated in vivo with high molecular weight complexes and coprecipitated with CDK2 and CDK4. We demonstrate by transfection experiments in SaOS-2 cells that p23 induces a G1 phase growth arrest by inhibition of cyclin/CDK2 activity. In summary we describe here a caspase-cleaved form of p27, induced in absence of detectable apoptosis and likely involved in cell cycle regulation.
 ...
PMID:Evidence for a p23 caspase-cleaved form of p27[KIP1] involved in G1 growth arrest. 1036 53

This study investigates the mechanisms underlying death of cultured embryonic cortical neurons exposed to the DNA-damaging agent camptothecin and in particular the interdependence of the roles of cyclin-dependent kinases (Cdks), caspases, and mitochondrial function. Camptothecin evokes rapid neuronal death that exhibits nuclear features of apoptosis. This death is accompanied by loss of cytochrome c and mitochondrial transmembrane potential as well as by induction of caspase-3-like activity and caspase-2 processing. The Cdk inhibitor flavopiridol provides long-term rescue from death and prevents loss of cytochrome c and mitochondrial transmembrane potential as well as caspase activation and processing. General caspase inhibitors rescue neurons from this rapid apoptotic death but do not prevent them from undergoing delayed death in which nuclear features of apoptosis are absent. Moreover, the caspase inhibitors do not affect early cytochrome c release and delay but do not prevent the loss of transmembrane potential. Agents that directly disrupt mitochondrial function without inducing cytochrome c release lead to a caspase-independent death. These observations favor a model in which (1) DNA damage leads to Cdk activation, which lies upstream of release of cytochrome c and caspase activation; (2) cytochrome c release is caspase-independent and may occur upstream of caspase activation; (3) early apoptotic death requires caspases; and (4) delayed nonapoptotic death that occurs in the presence of caspase inhibitors is a consequence of prolonged loss of mitochondrial function. These findings shed light on the mechanisms by which DNA damage kills neurons and raise questions regarding the general utility of caspase inhibitors as neurotherapeutic agents.
 ...
PMID:Caspase-dependent and -independent death of camptothecin-treated embryonic cortical neurons. 1041 53

We investigated the mechanisms by which calcitonin (CT) suppresses cellular proliferation, using HEK-293 cells stably transfected with either the rat C1a CT receptor (CTR) or the insert-negative form of the human CTR. CT treatment of clonal cell lines expressing either receptor type, but not untransfected HEK-293 cells, strongly suppressed cell growth in a concentration-dependent manner. The reduction in cell growth with CT treatment could not be attributed to cellular necrosis or apoptotic cell death, the latter assessed by both DNA fragmentation analysis and caspase 3 (CPP-32) assay. Growth inhibition was associated with an accumulation of cells in the G2 phase of the cell cycle. CT treatment of the human and rat CTR-expressing cell lines resulted in a rapid and sustained induction of mRNA encoding the cyclin-dependent kinase inhibitor, p21WAF1/CIP1, increased levels of which were maintained at least 48 h after initiation of treatment. Western blot analysis showed a rapid corresponding increase in p21WAF1/CIP1 protein, whereas protein levels of another member of the cyclin-dependent kinase inhibitor family, p27kip1, were unchanged. In parallel with the induction of p21, CT treatment reduced levels of p53 mRNA and protein. CT treatment resulted in a specific cell cycle block in G2, which was associated with inhibition of Cdc2/cyclin B kinase activity as measured by histone H1 phosphorylation. There was no evidence for p21 association with this complex despite the inhibition of Cdc2 activity. Evidence that p21 induction was causative of cell growth suppression was obtained from p21 antisense oligonucleotide experiments. Treatment with a p21 antisense oligonucleotide blocked induction of p21 expression and significantly reduced the CT-mediated growth inhibition. These observations suggest that p21 is required for the G2 arrest in response to CT, but argue against a direct role of p21 in the inhibition of Cdc2 activity. These studies suggest a novel regulation of cell cycle progression by CT and will provide a basis for detailed examination of the molecular mechanisms involved.
 ...
PMID:Calcitonin receptor-mediated growth suppression of HEK-293 cells is accompanied by induction of p21WAF1/CIP1 and G2/M arrest. 1051 75

Kaposi's sarcoma-associated herpesvirus (KSHV) has a key etiological role in development of Kaposi's sarcoma (KS). v-Cyclin is a KSHV-encoded homologue to D-type cyclins that associates with cellular cyclin-dependent kinase 6 (CDK6). v-Cyclin promotes S-phase entry of quiescent cells and has been suggested to execute functions of both D- and E-type cyclins. In this study, expression of v-cyclin in cells with elevated levels of CDK6 led to apoptotic cell death after the cells entered S phase. The cell death required the kinase activity of CDK6 because cells expressing a kinase-deficient form of CDK6 did not undergo apoptosis upon v-cyclin expression. Studies on the mechanisms involved in this caspase-3-mediated apoptosis indicated that it was independent of cellular p53 or pRb status, and it was not suppressed by Bcl-2. In contrast, the KSHV-encoded v-Bcl-2 efficiently suppressed v-cyclin-/CDK6-induced apoptosis, demonstrating a marked difference in the antiapoptotic properties of c-Bcl-2 and v-Bcl-2. In KS lesions, high CDK6 expression was confined to a subset of cells, some of which displayed signs of apoptosis. These results suggest that v-cyclin may exert both growth-promoting and apoptotic functions in KS, depending on factors regulating CDK6 and v-Bcl-2 levels.
 ...
PMID:Kaposi's sarcoma-associated herpesvirus-encoded v-cyclin triggers apoptosis in cells with high levels of cyclin-dependent kinase 6. 1051 12

Here we investigate the role of the control of apoptosis in normal cell division. We show that interference with the expression or function of the apoptosis inhibitor survivin causes caspase-dependent cell death in the G2/M phase of the cell cycle, and a cell-division defect characterized by centrosome dysregulation, multipolar mitotic spindles and multinucleated, polyploid cells. Use of a dominant-negative survivin mutant or antisense survivin complementary DNA disrupts a supramolecular assembly of survivin, caspase-3 and the cyclin-dependent-kinase inhibitor p21Waf1/Cip1 within centrosomes, and results in caspase-dependent cleavage of p21. Polyploidy induced by survivin antagonists is accentuated in p21-deficient cells, and corrected by exogenous expression of p21. These findings show that control of apoptosis and preservation of p21 integrity within centrosomes by survivin are required for normal mitotic progression.
 ...
PMID:Pleiotropic cell-division defects and apoptosis induced by interference with survivin function. 1058 56

Hereditary tyrosinemia type I is the most severe metabolic disease of the tyrosine catabolic pathway mainly affecting the liver. It is caused by deficiency of fumarylacetoacetate hydrolase, which prevents degradation of the toxic metabolite fumarylacetoacetate (FAA). We report here that FAA induces common effects (i.e., cell cycle arrest and apoptosis) in both human (HepG2) and rodent (Chinese hamster V79) cells, effects that seem to be temporally related. Both the antiproliferative and apoptosis-inducing activities of FAA are dose dependent and enhanced by glutathione (GSH) depletion with L-buthionine-(S,R)-sulfoximine (BSO). Short treatment (2 h) with 35 microM FAA/+BSO or 100 microM FAA/-BSO induced a transient cell cycle arrest at the G2/M transition (20% and 37%, respectively) 24 h post-treatment. In cells treated with 100 microM FAA/-BSO, an inactivation, followed by a rapid over-induction of cyclin B-dependent kinase occurred, which peaked 24 h post-treatment. Maximum levels of caspase-1 and caspase-3 activation were detected at 3 h and 32 h, respectively, whereas release of mitochondrial cytochrome c was maximal at 24-32 h post-treatment. The G2/M peak declined 24 h later, concomitantly with the appearance of a sub-G1, apoptotic population showing typical nucleosomal-sized DNA fragmentation and reduced mitochondrial transmembrane potential (Deltapsi(m)). These events were prevented by the general caspase inhibitor z-VAD-fmk, whereas G2/M arrest and subsequent apoptosis were abolished by GSH-monoethylester or N-acetylcysteine. Other tyrosine metabolites, maleylacetoacetate and succinylacetone, had no antiproliferative effects and induced only very low levels of apoptosis. These results suggest a modulator role of GSH in FAA-induced cell cycle disturbance and apoptosis where activation of cyclin B-dependent kinase and caspase-1 are early events preceding mitochondrial cytochrome c release, caspase-3 activation, and Deltapsi(m) loss. -Jorquera, R., Tanguay, R. M. Cyclin B-dependent kinase and caspase-1 activation precedes mitochondrial dysfunction in fumarylacetoacetate-induced apoptosis.
 ...
PMID:Cyclin B-dependent kinase and caspase-1 activation precedes mitochondrial dysfunction in fumarylacetoacetate-induced apoptosis. 1059 76


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