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Query: UNIPROT:P42574 (
caspase-3
)
45,978
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
We assessed the possible role of interleukin-1beta-converting enzyme-family proteases (caspases) in apoptosis in cultured rat cerebellar granule neurons. CPP32 (
caspase-3
)-like protease activity was augmented by low KCl treatment, preceding neuronal cell death. Agents such as brain-derived neurotrophic factor (BDNF), dibutylyl cAMP, NMDA, actinomycin D, S-adenosyl-L-methionine, and spermine prevented apoptosis. For various neuroprotective agents, the degree of apoptosis prevention correlated with the prevention of the activation of CPP32-like protease. Furthermore, Z-
Asp
-2, 6-dichlorobenzoyloxy-methylketone (Z-Asp-CH2-DCB), Boc-
Asp
-fluoromethylketone (Boc-Asp-FMK), and Z-Val-Ala-
Asp
-fluoromethylketone (Z-VAD-FMK), which are inhibitors of caspases, also prevented apoptosis. In contrast to many other neuroprotective agents, these inhibitors of caspases showed little effect on the decrease of cellular 3-[4,5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide (MTT) reduction activity after low KCl treatment. The neurons rescued by these inhibitors of caspases during low KCl treatment were in a hypoenergic state in their ATP levels and vulnerable to subsequent treatment with medium containing high KCl or glutamate which induce an influx of Ca2+, but which are less toxic to normal neurons. These results suggest that caspase(s) are involved in the apoptosis of cerebellar granule neurons and that several agents protect neurons from death by blocking the activation of the protease(s). Although several caspase inhibitors examined in this study protect neurons from apoptosis, rescued neurons are vulnerable to subsequent stimuli that induce necrotic cell death.
...
PMID:Inhibitors of interleukin-1 beta-converting enzyme-family proteases (caspases) prevent apoptosis without affecting decreased cellular ability to reduce 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide in cerebellar granule neurons. 963 Jun 48
To dissect intracellular pathways involved in B cell Ag receptor (BCR)-mediated and Fas-induced human B cell death, we isolated clones of the Burkitt lymphoma cell line Ramos with different apoptosis sensitivities. Selection for sensitivity to Fas-induced apoptosis also selected for clones with enhanced BCR death sensitivity and vice versa. In contrast, clones resistant to Fas-mediated apoptosis could still undergo BCR-induced cell death. Based on the functional phenotypes of these clones, we hypothesized that both receptor-induced apoptosis pathways are initially distinct but may eventually converge. Indeed, ligation of both Fas and BCR resulted in cleavage of the IL-1beta-converting enzyme/Ced-3-like protease
caspase 3
and its substrates Ac-
Asp
-Glu-Val-
Asp
-aldehyde and poly(ADP-ribose) polymerase. Markedly, qualitative differences in the
caspase 3
cleavage pattern induced by Fas or BCR ligation were observed; whereas Fas ligation generated
caspase 3
cleavage products of 19/20 and 17 kDa, only the latter cleavage product was found upon BCR cross-linking. The caspase inhibitor Val-Ala-
Asp
-fluoromethylketone blocked both Fas- and BCR-mediated apoptosis, but differentially affected
caspase 3
cleavage induced by either stimulus. Finally, overexpression of a Fas-associated death domain (FADD) dominant-negative mutant protein was found to inhibit Fas-induced apoptosis but not BCR-induced apoptosis. Together our findings imply that Fas and BCR couple, via FADD-dependent and FADD-independent mechanisms, respectively, to distinct proteases upstream of
caspase 3
.
...
PMID:Dissection of pathways leading to antigen receptor-induced and Fas/CD95-induced apoptosis in human B cells. 963 25
Caspase activation has been shown to be a critical step in several models of neuronal apoptosis such as staurosporine treatment of human neuroblastoma SH-SY5Y cells and potassium deprivation of rat cerebellar granule neurons. One common event is the appearance of caspase-mediated 120-kDa nonerythroid alpha-spectrin breakdown product (SBDP120). Second, inhibitors of the caspase family are effective blockers of such neuronal death. In this study, we report the appearance of caspase-mediated SBDP120 in excitotoxin-challenged fetal rat cerebrocortical neurons [N-methyl-D-aspartate (NMDA), alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid, and kainate] and rat cerebellar granule neurons (NMDA and kainate). A general caspase inhibitor, carbobenzoxy-
Asp
-CH2OC(O)-2,6-dichlorobenzene (Z-D-DCB), blocked the formation of SBDP120 under these conditions and attenuated the observed NMDA-induced lactate dehydrogenase (LDH) release in both cell types. Furthermore, hydrolytic activity toward a
caspase-3
-preferred synthetic peptide substrate, acetyl-DEVD-7-amido-4-methylcoumarin, was significantly elevated in NMDA-treated granule neurons. Lastly, oxygen-glucose deprivation (OGD)-challenged cerebrocortical cultures also showed the appearance of SBDP120. Again, Z-D-DCB blocked the SBDP120 formation as well as attenuated the LDH release from the OGD-challenged neurons. Taken together, the presence of caspase-specific SBDP120 and the neuroprotective effects of Z-D-DCB strongly suggest that caspase activation contributes at least in part to excitotoxin- and OGD-induced neuronal death.
...
PMID:Evidence for activation of caspase-3-like protease in excitotoxin- and hypoxia/hypoglycemia-injured neurons. 964 65
Activation of procaspase-9 by Apaf-1 in the cytochrome c/dATP-dependent pathway requires proteolytic cleavage to generate the mature caspase molecule. To elucidate the mechanism of activation of procaspase-9 by Apaf-1, we designed an in vitro Apaf-1-procaspase-9 activation system using recombinant components. Here, we show that deletion of the Apaf-1 WD-40 repeats makes Apaf-1 constitutively active and capable of processing procaspase-9 independent of cytochrome c an dATP. Apaf-1-mediated processing of procaspase-9 occurs at
Asp
-315 by an intrinsic autocatalytic activity of procaspase-9 itself. We provide evidence that Apaf-1 can form oligomers and may facilitate procaspase-9 autoactivation by oligomerizing its precursor molecules. Once activated, caspase-9 can initiate a caspase cascade involving the downstream executioners
caspase-3
, -6, and -7.
...
PMID:Autoactivation of procaspase-9 by Apaf-1-mediated oligomerization. 965 78
Apoptosis, often also termed "programmed cell death", occurs in normal development in the brain and spinal cord. Important to concepts of disease and potential intervention is the exciting finding that apoptosis is also found after neurotrauma and in a number of neurodegenerative diseases. Although the precise mechanism of neuronal cell loss remains unknown, much emphasis has been placed recently on the activation of cell death protease cascades within the cell. How these cascades may be activated, especially from extracellular influences, is currently poorly understood. Thrombin, the multifunctional coagulation protease, is an early phase modulator at sites of tissue injury and has been shown to induce cell death in neurons by an apoptotic mechanism by activating its receptor, PAR-1. Using a model motor neuronal cell line, NSC19, which we have shown undergoes apoptosis after treatment with classic apoptosis inducers such as the topoisomerase inhibitors camptothecin and etoposide, we unambiguously found that nanomolar thrombin induced characteristic signs of apoptosis. Strikingly, endonucleolysis was accompanied by an increase in
caspase-3
-like activity in cellular extracts, which correlated with both detection of caspase-induced signature cleavage of the cortical cytoskeleton component nonerythroid spectrin (alpha-fodrin) and identification of increased accessibility of a caspase cleavage domain, using an antibody (Ab127) made against a synthetic peptide KGDEVD. Demonstrating that thrombin activation of death proteases was linked to cell death, we were able to inhibit thrombin-induced apoptosis by using a caspase family inhibitor, benzyloxycarbonyl-
Asp
-(oMe)-fluoromethyl ketone (Boc-D-FMK). These novel results demonstrate that thrombin serves as an extracellular "death signal" to activate intracellular protease pathways. These pathways lead to apoptotic cell death and can be modulated by inhibiting caspase activity downstream to PAR-1.
...
PMID:Thrombin is an extracellular signal that activates intracellular death protease pathways inducing apoptosis in model motor neurons. 965 39
Osteoclast-like multinucleated cells (OCLs) were prepared on collagen gels in a coculture system of mouse bone marrow cells and osteoblasts, and purified by collagenase and a subsequent pronase treatment. More than 80% of the purified OCLs were found to undergo apoptotic cell death by 48 h during the culture in a culture medium containing 10% fetal bovine serum (FBS). Withdrawal of FBS from the culture medium accelerated the cell death, which induced more than 80% of OCLs to undergo apoptotic cell death by as early as 18 h. Two peptide inhibitors of caspases (interleukin-1beta-converting enzyme family proteases), benzyloxycarbonyl-Val-Ala-
Asp
(OMe)-fluoromethyl ketone (Z-VAD-FMK) and benzyloxycarbonyl-
Asp
-Glu-Val-
Asp
(OMe)-fluoromethyl ketone (Z-DEVD-FMK), extended the survival time of OCLs in the presence and absence of 10% FBS, but the effect was rather limited in the absence of FBS. Because interleukin-1alpha (IL-1alpha) and the macrophage colony stimulating factor (M-CSF) are known to promote the survival of osteoclasts, we examined the effect of the peptide inhibitors and these cytokines. Combinations of the peptide inhibitors and IL-1alpha, or the peptide inhibitors and M-CSF, were more effective than the inhibitors alone. When endogenous caspase activities of OCLs were analyzed using fluorescence peptide substrates, the activities, in particular,
caspase-3
(CPP32)-like activity, were markedly increased in OCLs by the withdrawal of FBS from the culture medium. IL-1alpha and M-CSF suppressed the activation of the caspases. In addition, western blot analysis revealed that the expression of Bcl-2, which inhibits the activation of caspases, was very weak or even negligible in OCLs. Taken together, these results suggest that the caspases are involved in the regulation of survival and apoptotic cell death of osteoclasts.
...
PMID:Caspases (interleukin-1beta-converting enzyme family proteases) are involved in the regulation of the survival of osteoclasts. 966 28
Nitric oxide (NO) promotes apoptotic cell death in the mouse macrophage cell line RAW 264.7 and in the human promyelocytic leukaemia cell line U937, which exemplifies p53-dependent and p53-independent executive death pathways. Here, we followed the cleavage of two caspase substrates during NO-intoxication, assaying poly(ADP-ribose) polymerase and U1-70kDa small ribonucleoprotein (U1-70kDa) degradation. By using pharmacological inhibitors, we found that Z-aspartyl-2,6-dichlorobenzoyloxymethylketone (Z-
Asp
-CH2-DCB; 100 microM), a caspase-like protease inhibitor, completely blocked S-nitrosoglutathione (GSNO)-induced apoptosis in both RAW 264.7 and U937 cells (IC50 = 50 microM for RAW 264.7 macrophages vs. IC50 = 33 microM for U937 cells). Notably, a characterized
caspase-3
(Ac-DEVD-CHO) inhibitor left NO-induced DNA fragmentation and the appearance of an apoptotic morphology unaltered, although completely blocking
caspase-3
activity. However, Z-
Asp
-CH2-DCB suppressed protease-mediated U1-70kDa cleavage and DNA fragmentation in parallel. In contrast, poly(ADP-ribose) polymerase cleavage in U937 cells was only delayed by Z-
Asp
-CH2-DCB, while poly(ADP-ribose) polymerase digestion in RAW 264.7 macrophages proceeded unaltered. We further compared U1-70kDa and poly(ADP-ribose) polymerase cleavage in stably Bcl-2 transfected RAW 264.7 macrophages. Rbcl2-2, a Bcl-2 overexpressing clone, suppressed DNA fragmentation and U1-70kDa digestion in response to GSNO, although allowing delayed but complete poly(ADP-ribose) polymerase degradation. Conclusively, poly(ADP-ribose) polymerase cleavage not causatively coincided with the appearance of other apoptotic parameters. Our results suggest that NO-induced apoptosis demands a Z-
Asp
-CH2-DCB inhibitable caspase activity, most likely distinct from
caspase-3
and caspase-1. NO-mediated executive apoptotic signaling results in U1-70kDa and poly(ADP-ribose) polymerase cleavage. Whereas U1-70kDa digestion closely correlates to the occurrence of apoptotic parameters such as DNA fragmentation or an apoptotic morphology, poly(ADP-ribose) polymerase-breakdown does not.
...
PMID:Protease activation during nitric oxide-induced apoptosis: comparison between poly(ADP-ribose) polymerase and U1-70kDa cleavage. 967 Nov 15
Monocytic-like leukemia U-937 cells rapidly undergo morphological changes and DNA fragmentation that is typical of apoptosis following treatment with DNA topoisomerase I inhibitor [20-S-camptothecin lactone (CPT)]. The tripeptide derivative benzyloxycarbonyl-Val-Ala-
Asp
(OMe)fluoromethyl ketone blocks
Asp
-Glu-Val-
Asp
-ase (DEVDase) activity and prevents the occurrence of high molecular weight and oligonucleosome-sized DNA fragments associated with apoptosis in CPT-treated cells. In contrast, N-tosyl-L-phenylalanylchloromethyl ketone (TPCK) does not prevent DEVDase activity and high molecular weight DNA fragmentation but completely abrogates the appearance of oligonucleosome-sized DNA fragmentation. These results suggest that
caspase 3
-like activities are involved with high molecular weight DNA fragmentation pathway, whereas TPCK-sensitive activities are involved in oligonucleosome-sized DNA fragmentation pathway in CPT-treated cells. Electron micrographs reveal that caspase inhibition by benzyloxycarbonyl-Val-Ala-
Asp
(OMe)fluoromethyl ketone also abrogates the typical morphological changes associated with apoptosis, whereas TPCK does not delay these morphological changes that are typical of apoptosis. Caspase inhibition slows passage of the cells through G2 and causes a transient accumulation of these cells at the G0/G1 phase of the cell cycle following CPT treatment. In a cell-free system, when purified nuclei are incubated with apoptotic cytosolic extracts obtained from CPT-treated U-937 cells, TPCK causes a similar effect in abrogating the oligonucleosome-sized DNA fragmentation but does not affect DEVDase activity. Addition of either benzyloxycarbonyl-Val-Ala-
Asp
-free carboxyl group or acetyl-
Asp
-Glu-Val-
Asp
-aldehyde completely inhibits DEVDase activity in these extracts. However, acetyl-
Asp
-Glu-Val-
Asp
-aldehyde does not affect the occurrence of oligonucleosome-sized DNA fragmentation in the cell-free system, whereas the benzyloxycarbonyl derivatives benzyloxycarbonyl-Val-Ala-
Asp
-free carboxyl group, benzyloxycarbonyl-Val-Ala-free hydroxyl group, benzyloxycarbonyl-Val-free hydroxyl group, and benzyloxycarbonyl hydrazide abolish it markedly. Taken together, these observations show the pivotal role of DEVDase activity in triggering the apoptotic process and high molecular weight DNA fragmentation, whereas TPCK- and benzyloxycarbonyl-sensitive activities are involved in the oligonucleosome-sized DNA fragmentation pathway induced by CPT.
...
PMID:Distinct steps in DNA fragmentation pathway during camptothecin-induced apoptosis involved caspase-, benzyloxycarbonyl- and N-tosyl-L-phenylalanylchloromethyl ketone-sensitive activities. 967 72
We have previously demonstrated cleavage of alpha-spectrin by
caspase-3
and calpain during apoptosis in SH-SY5Y neuroblastoma cells (Nath, R., Raser, K. J., Stafford, D., Hajimohammadreza, I., Posner, A., Allen, H., Talanian, R. V., Yuen, P., Gilbertsen, R. B., and Wang, K. K. (1996) Biochem. J. 319, 683-690). We demonstrate here that calcium/calmodulin-dependent protein kinase IV (CaMK IV) is cleaved during apoptosis by
caspase-3
and calpain. We challenged SH-SY5Y cells with the pro-apoptotic agent thapsigargin. Western blot analysis revealed major CaMK IV breakdown products of 40, 38, and 33 kDa. Digestion of control SH-SY5Y lysate with purified
caspase-3
produced a 38-kDa CaMK IV fragment; digestion with purified calpain produced a major fragment of 40 kDa. Pretreatment with carbobenzoxy-
Asp
-CH2OC(O)-2,6-dichlorobenzene or Z-Val-Ala-
Asp
-fluoromethylketone was able to block the
caspase-3
-mediated production of the 38-kDa fragment both in situ and in vitro. Calpain inhibitor II similarly blocked formation of the calpain-mediated 40-kDa fragment both in situ and in vitro. Digestion of recombinant CaMK IV by other caspase family members revealed that only
caspase-3
produces a fragmentation pattern consistent to that seen in situ. The major
caspase-3
and calpain cleavage sites are respectively identified as PAPD176*A and CG201*A, both within the CaMK IV catalytic domain. Furthermore, calmodulin-stimulated protein kinase activity decreases within 6 h in thapsigargin-treated SH-SY5Y. The loss of activity precedes cell death.
...
PMID:Calcium/calmodulin-dependent protein kinase IV is cleaved by caspase-3 and calpain in SH-SY5Y human neuroblastoma cells undergoing apoptosis. 968 36
Cytototoxic T lymphocyte-induced apoptosis can occur either through the directed exocytosis of granzyme B and perforin or via ligation of Fas. Both pathways involve the activation of a family of cysteine proteinases, the caspases, that cleave substrates at
aspartic acid
and are themselves activated by cleavage at internal aspartate residues. Fas recruits caspase 8, which initiates the death program through the subsequent activation of
caspase 3
. Granzyme B can process both caspase 8 and 3 in vitro, suggesting that both Fas and granzyme B access the apoptotic program in the same way. Here we demonstrate that although the two mechanisms are similar, the events that lead to activation of
caspase 3
can be distinguished in vivo on the basis of their sensitivities to both pharmacological and virus-encoded caspase inhibitors. In cytotoxic T lymphocytes-mediated death the initial cleavage event on
caspase 3
is insensitive to benzyloxycarbonyl-Val-Ala-
Asp
fluoromethyl ketone (zVAD-fmk) inhibition in both mouse and human systems. During Fas-mediated death, however, activation of
caspase 3
is completely inhibited to zVAD-fmk. In addition, the viral serpin SPI-2, a homologue of cytokine response modifier A (crmA), is an effective inhibitor of the Fas but not the granzyme pathway. Our results demonstrate that whereas Fas-mediated activation of
caspase 3
requires an upstream caspase activity that is zVAD-fmk-sensitive, the initial cleavage of
caspase 3
during granule-mediated cell death is insensitive to zVAD-fmk, suggesting that
caspase 3
is cleaved directly by granzyme B in vivo.
...
PMID:Cytotoxic T lymphocyte-assisted suicide. Caspase 3 activation is primarily the result of the direct action of granzyme B. 969 85
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