Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.22.56 (caspase-3)
 35,750 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Caffeic acid phenethyl ester (CAPE), which is derived from the propolis of honeybee hives, has been shown to block tumor promotion and to have toxic effects on several cancer cells. The mechanism of the anti-tumor promotion activity of CAPE is unclear, however. In this study, we found that CAPE suppressed 12-O-tetradecanoylphorbol-13-acetate-induced cell transformation and induced apoptosis in mouse epidermal JB6 Cl 41 cells. No difference in induction of apoptosis was observed between normal lymphoblasts and sphingomyelinase-deficient cell lines. Although CAPE treatment of two p53 mutant tumor cell lines, NCI-H358 and SK-OV-3, and p53-deficient (p53(-/-)) cells caused the cleavage of caspase-3 as well as DNA fragmentation, caspase-3 cleavage was seen early (at 6 h) only in cells expressing wild-type p53 (p53(+/+)) and Cl 41 cells. These results suggested that p53 may be involved in the early stage of CAPE-induced apoptosis. The p53-dependent transcription activation occurred 2 h after treatment with CAPE and reached a maximum at 6 h in Cl 41 p53 DNA-binding sequence stable transfectant cells. In addition, phosphorylation of p53 at serine 15 and serine 392 was induced in Cl 41 cells within 6 h after treatment with CAPE. Therefore, CAPE may induce apoptosis through p53-dependent and p53-independent pathways and its anti-tumor promotion activity may have occurred through the induction of apoptosis.
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PMID:Suppression of cell transformation and induction of apoptosis by caffeic acid phenethyl ester. 1142 85

The ability of insulin to protect neurons from apoptosis was examined in differentiated R28 cells, a neural cell line derived from the neonatal rat retina. Apoptosis was induced by serum deprivation, and the number of pyknotic cells was counted. p53 and Akt were examined by immunoblotting after serum deprivation and insulin treatment, and caspase-3 activation was examined by immunocytochemistry. Serum deprivation for 24 h caused approximately 20% of R28 cells to undergo apoptosis, detected by both pyknosis and activation of caspase-3. 10 nm insulin maximally reduced the amount of apoptosis with a similar potency as 1.3 nm (10 ng/ml) insulin-like growth factor 1, which acted as a positive control. Insulin induced serine phosphorylation of Akt, through the phosphatidylinositol (PI) 3-kinase pathway. Inhibition of PI 3-kinase with wortmannin or LY294002 blocked the ability of insulin to rescue the cells from apoptosis. SN50, a peptide inhibitor of NF-kappaB nuclear translocation, blocked the rescue effect of insulin, but neither insulin or serum deprivation induced phosphorylation of IkappaB. These results suggest that insulin is a survival factor for retinal neurons by activating the PI 3-kinase/Akt pathway and by reducing caspase-3 activation. The rescue effect of insulin does not appear to be mediated by NF-kappaB or p53. These data suggest that insulin provides trophic support for retinal neurons through a PI 3-kinase/Akt-dependent pathway.
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PMID:Insulin rescues retinal neurons from apoptosis by a phosphatidylinositol 3-kinase/Akt-mediated mechanism that reduces the activation of caspase-3. 1144 30

Apoptosis induced in the IL3-dependent murine pro-B lymphocytic (FL5.12) cell line by the 5-lipoxygenase activating protein inhibitor MK886 is accompanied by the rapid loss of the anti-apoptotic bcl-x(L) and bcl-2, but not the proapoptotic bax proteins (Datta et al., J. Biol. Chem. 273, 28163-28169, 1998). Since several reports indicate important roles for noncaspase proteases in apoptosis, the participation of lysosomes, as well as serine, cysteine, or aspartic acid proteases, in the effects of MK886 were investigated. Consistent with the involvement of various proteases, lysosomal degranulation was evident, as observed by a decrease in acridine orange fluorescence at 2 h and an increase in cytosolic beta-hexosaminidase activity at 4 h after treating FL5.12 cells with 10 microM MK886. The disappearance of bcl-x(L) from FL5.12 cells upon MK886 treatment was prevented in a dose-dependent manner by pretreatment with leupeptin, pepstatin, phenylmethylsulfonyl fluoride, or the broad-spectrum caspase inhibitor Boc-D-FMK. Each of the noncaspase protease inhibitors partially inhibited MK886-induced apoptosis as measured by phosphatidylserine externalization and DNA fragmentation. The noncaspase inhibitors also blocked about half of the increase in caspase-3-like activity. Boc-D-FMK completely inhibited this enzyme and prevented apoptosis. None of the inhibitors were able to directly inhibit activated caspase-3 in cell lysates, suggesting their effects were upstream of caspase activation. These observations suggest the involvement of various proteases, possibly originating from lysosomes, upstream of active caspase-3, in the loss of bcl-x(L) protein and in the signaling pathway of MK886-induced apoptosis in FL5.12 cells. This pathway may be unique to MK886 since these same protease inhibitors had only minimal effects on etoposide-induced apoptosis and the accompanying moderate loss of bcl-x(L) in FL5.12 cells.
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PMID:Proteolytic loss of bcl-x(L) in FL5.12 Cells undergoing apoptosis induced by MK886. 1148 88

The goal of this study was to determine whether the intracellular distribution of the proapoptotic enzyme glycogen synthase kinase-3 beta (GSK-3 beta) is dynamically regulated by conditions that activate apoptotic signaling cascades. In untreated human neuroblastoma SH-SY5Y cells, GSK-3 beta was predominantly cytosolic, although a low level was also detected in the nucleus. The nuclear level of GSK-3 beta was rapidly increased after exposure of cells to serum-free media, heat shock, or staurosporine. Although each of these conditions caused changes in the serine 9 and/or tyrosine phosphorylation of GSK-3 beta, neither of these modifications was correlated with nuclear accumulation of GSK-3 beta. Heat shock and staurosporine treatments increased nuclear GSK-3 beta prior to activation of caspase-9 and caspase-3, and this nuclear accumulation of GSK-3 beta was unaltered by pretreatment with a general caspase inhibitor. The GSK-3 beta inhibitor lithium did not alter heat shock-induced nuclear accumulation of GSK-3 beta but increased the nuclear level of cyclin D1, indicating that cyclin D1 is a substrate of nuclear GSK-3 beta. Thus, the intracellular distribution of GSK-3 beta is dynamically regulated by signaling cascades, and apoptotic stimuli cause increased nuclear levels of GSK-3 beta, which facilitates interactions with nuclear substrates.
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PMID:Proapoptotic stimuli induce nuclear accumulation of glycogen synthase kinase-3 beta. 1149 16

During gestation, the uterus undergoes severe changes to accommodate and protect the developing conceptus. In particular, stromal endometrial cells proliferate and differentiate to form the decidual tissue, which produces PRL. Once the conceptus begins to grow, extensive regression by apoptosis take place in the decidua coincident with the loss of the PRL receptor in this tissue. In this report we have established for the first time that PRL, acting through the long form of the PRL receptor and the PI3K pathway, exerts an antiapoptotic effect in rat decidua. We have also shown that protein kinase B phosphorylation on serine 473 as well as its nuclear translocation are stimulated by PRL in decidual cells. Moreover, we have found that caspase-3, a well known effector of apoptosis, becomes expressed and active in the rat decidua just at a time when this tissue undergoes extensive apoptosis. PRL was able to down-regulate both caspase-3 mRNA levels as well as activity. Furthermore, using a protein kinase B dominant-negative expression vector, we provide evidence that PRL inhibition of caspase-3 requires an intact protein kinase B pathway. Finally, we have also found that rat placental lactogen I and II dose-dependently inhibit caspase-3 mRNA, suggesting multiple sources of PRL in the hormonal control of rat decidual regression. In summary, the results of this study have defined an important role for decidual PRL in the normal progress of pregnancy, specifically in the regression and reorganization of the decidua.
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PMID:PRL antiapoptotic effect in the rat decidua involves the PI3K/protein kinase B-mediated inhibition of caspase-3 activity. 1151 88

The group VIA PLA2 is a member of the PLA2 superfamily. This enzyme, which is cytosolic and Ca2+-independent, has been designated iPLA2beta to distinguish it from another recently cloned Ca2+-independent PLA2. Features of iPLA2beta molecular structure offer some insight into possible cellular functions of the enzyme. At least two catalytically active iPLA2beta isoforms and additionalsplicing variants are derived from a single gene that consists of at least 17 exons located on human chromosome 22q13.1. Potential tumor suppressor genes also reside at or near this locus. Structural analyses reveal that iPLA2beta contains unique structural features that include a serine lipase consensus motif (GXSXG), a putative ATP-binding domain, an ankyrin-repeat domain, a caspase-3 cleavage motif DVTD138Y/N, a bipartite nuclear localization signal sequence, and a proline-rich region in the human long isoform. iPLA2beta is widely expressed among mammalian tissues, with highest expression in testis and brain. iPLA2beta prefers to hydrolyze fatty acid at the sn-2 fatty acid substituent but also exhibits phospholipase A1, lysophospholipase, PAF acetylhydrolase, and transacylase activities. iPLA2beta may participate in signaling, apoptosis, membrane phospholipid remodeling, membrane homeostasis, arachidonate release, and exocytotic membrane fusion. Structural features and the existence of multiple splicing variants of iPLA2beta suggest that iPLA2beta may be subject to complex regulatory mechanisms that differ among cell types. Further study of its regulation and interaction with other proteins may yield insight into how its structural features are related to its function.
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PMID:The molecular biology of the group VIA Ca2+-independent phospholipase A2. 1152 80

MNEI (monocyte/neutrophil elastase inhibitor) is a 42 kDa serpin superfamily protein characterized initially as a fast-acting inhibitor of neutrophil elastase. Here we show that MNEI has a broader specificity, efficiently inhibiting proteases with elastase- and chymotrypsin-like specificities. Reaction of MNEI with neutrophil proteinase-3, an elastase-like protease, and porcine pancreatic elastase demonstrated rapid inhibition rate constants >10(7) M(-1) s(-1), similar to that observed for neutrophil elastase. Reactions of MNEI with chymotrypsin-like proteases were also rapid: cathepsin G from neutrophils (>10(6) M(-1) s(-1)), mast cell chymase (>10(5) M(-1) s(-1)), chymotrypsin (>10(6) M(-1) s(-1)), and prostate-specific antigen (PSA), which had the slowest rate constant at approximately 10(4) M(-1) s(-1). Inhibition of trypsin-like (plasmin, granzyme A, and thrombin) and caspase-like (granzyme B) serine proteases was not observed or highly inefficient (trypsin), nor was inhibition of proteases from the cysteine (caspase-1 and caspase-3) and metalloprotease (macrophage elastase, MMP-12) families. The stoichiometry of inhibition for all inhibitory reactions was near 1, and inhibitory complexes were resistant to dissociation by SDS, further indicating the specificity of MNEI for elastase- and chymotrypsin-like proteases. Determination of the reactive site of MNEI by N-terminal sequencing and mass analysis of reaction products identified two reactive sites, each with a different specificity. Cys(344), which corresponds to Met(358), the P(1) site of alpha1-antitrypsin, was the inhibitory site for elastase-like proteases and PSA, while the preceding residue, Phe(343), was the inhibitory site for chymotrypsin-like proteases. This study demonstrates that MNEI has two functional reactive sites corresponding to the predicted P(1) and P(2) positions of the reactive center loop. The data suggest that MNEI plays a regulatory role at extravascular sites to limit inflammatory damage due to proteases of cellular origin.
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PMID:The serpin MNEI inhibits elastase-like and chymotrypsin-like serine proteases through efficient reactions at two active sites. 1174 53

Gamma-interferon (IFN-gamma) a cytokine produced by CD4+ T helper type 1 cells, CD8+ T cells and natural killer (NK) cells, plays a central role in the development of humoral and cell-mediated immunity. IFN-gamma participates in the maturation and differentiation of B cells, but it has been previously reported that IFN-gamma may inhibit the early stages of B cell activation. We report that the inhibition of the B lymphoma cell WEHI-279-proliferation induced by IFN-gamma, involves the induction of typical features of apoptosis (nuclear chromatin condensation and fragmentation, cell shrinkage, phosphatidyl-serine (PS) exposure and mitochondrial membrane potential (delta psim) loss). IFN-gamma-mediated B cell apoptosis was decreased by the addition of the T helper type 2 cytokine, IL-4. WEHI-279 cells express CD95 and undergo apoptosis after treatment with either an agonistic anti-CD95 Ab or with a soluble recombinant CD95L. However, incubation with CD95-Fc or TRAIL-R1-Fc fusion proteins, did not prevent IFN-gamma-mediated apoptosis, suggesting that IFN-gamma-mediated apoptosis occurs independently of CD95/CD95L and TRAIL-R/TRAIL interactions. IFN-gamma-mediated apoptosis is associated with caspase-3 activation that can be prevented by the addition of the broad caspase inhibitor zVAD-fmk. These data indicate that IFN-gamma may play a major role in the regulation of B cell apoptosis, and suggest the involvement of an alternative pathway which is independent of the death receptors.
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PMID:Gamma-interferon induces apoptosis of the B lymphoma WEHI-279 cell line through a CD95/CD95L-independent mechanism. 1178 Nov 85

A number of inflammatory cytokines and growth factors promote monocyte survival; however, the biochemical events stimulated by these factors are poorly defined. We previously showed that the monocyte survival factor macrophage colony-stimulating factor (M-CSF) activated monocyte survival through a PI 3-kinase-dependent pathway resulting in the phosphorylation of Akt and the suppression of the activation of caspase-3. Because other cytokines and bacterial cell wall products also induce monocyte survival, we hypothesized that these factors may also suppress caspase-3 and caspase-9 activation and activate Akt in human monocytes. To test this hypothesis, we found that interleukin (IL)-1beta, tumor necrosis factor (TNF)-alpha, lipopolysaccharide (LPS), granulocyte macrophage-colony-stimulating factor (GM-CSF), and IL-18 appeared to suppress DNA fragmentation, caspase-9, and caspase-3 activation in human monocytes. Moreover, these stimuli appeared to induce the serine and threonine phosphorylation of Akt, which was reduced by the PI 3-kinase inhibitor LY294002. Using in vitro kinase assays, M-CSF appeared to induce more Akt activity than did the other survival factors. Treatment of monocytes with either LY294002 or wortmannin resulted in caspase-3 activation in the presence of these survival factors. These results suggest that monocyte survival factors may suppress DNA fragmentation, caspase-9, and caspase-3 activation in a PI 3-kinase-dependent manner, perhaps through the activation of Akt.
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PMID:Monocyte survival factors induce Akt activation and suppress caspase-3. 1180 74

Disruption of mitochondrial electron transport and opening of the so-called mitochondrial permeability transition pores (PTPs) are early events in apoptotic cell death and may be caused by the uncoupler of mitochondrial oxidation and phosphorylation, carbonyl cyanide p-trifluoromethoxyphenylhydrazone (FCCP). We investigated the cellular toxicity of FCCP in HL60 and CCRF-CEM cells alone or in combination with the known apoptosis inducers such as inhibitor of serine/threonine protein kinases staurosporine (Sts) and protein kinase C inhibitor chelerythrine. FCCP induced apoptotic cell death in both cell lines in a dose-dependent manner, and we were able to demonstrate an appearance of caspase-3-dependent PARP cleavage fragments with Western blot and the appearance of large (15-50 kb) DNA fragments using pulsed-field gel electrophoresis. After 2 hr of incubation with Che or Sts more than half of the cells had died by apoptosis. We observed a statistically significant delay in Sts- and Che-induced apoptotic cell death in CCRF-CEM cells when the cells were preincubated with FCCP but not with zVAD-FMK: about 50% more cells survived after pre-treatment with FCCP, as compared to 1 hr treatment with Che alone (P<0.05), and 25% more cells were alive after 6 hr of treatment, as compared to 6 hr exposure to Sts alone (P<0.05). The protective effect of FCCP was, however, transient and lasted only 6 hr. Treatment with aurintricarboxylic acid completely prevented Che- and Sts-induced apoptotic cell death in CCRF-CEM and HL60 cells. Incubation with Che resulted in a drop in the intracellular ATP content, predominantly distinctive in HL60, and in NAD(+) content in CCRF-CEM cells. Both ATP and NAD(+) drop were prevented with ATA, but not with FCCP or zVAD. Our data suggest that treatment with uncouplers of oxidative phosphorylation can induce apoptotic cell death in haematopoietic cell lines. However, when used in combination with serine/threonine protein kinase inhibitors FCCP can even prevent apoptosis.
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PMID:Modulation of apoptosis by mitochondrial uncouplers: apoptosis-delaying features despite intrinsic cytotoxicity. 1185 98


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