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Query: UNIPROT:P42574 (
caspase-3
)
45,978
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Upon transforming growth factor-beta (TGF-beta) treatment, Ramos cells, a B-cell lymphoma cell line, undergo apoptosis, as measured by annexin V labeling, DNA fragmentation, and propidium iodide staining. Apoptosis could be observed by 24 h after TGF-beta exposure and occurred before the development of a significant blockage of cell cycle progression. TGF-beta-mediated apoptosis was also accompanied by a strong induction of
caspase-3
subfamily activity. Incubation of cells with the caspase inhibitor Z-VAD.FMK at 20 microM, but not at 10 microM, prevented TGF-beta-induced apoptosis from occurring. By comparison,
caspase-3
subfamily activity was 87% inhibited at 10 microM Z-VAD.FMK and completely inhibited at 20 microM. Because of TGF-beta's well-established role of regulating gene transcription, the mRNA levels for proteins associated with apoptosis (Fas- and Fas-associated proteins,
Bcl-2
family members, IAP proteins, and I kappa B) were also studied. After 24 h of TGF-beta treatment, the most significant mRNA changes occurred with Bcl-XL (two-fold decrease) and Bik (twofold increase). TGF-beta treatment also resulted after 48 h in a fivefold decrease in Bcl-XL protein levels, based on immunoblotting analysis. Therefore, TGF-beta-mediated apoptosis involves the activation of caspases. In addition, TGF-beta transcriptionally regulates
Bcl-2
family members, Bcl-XL and Bik, to further influence the apoptosis process.
...
PMID:Transforming growth factor-beta-mediated apoptosis in the Ramos B-lymphoma cell line is accompanied by caspase activation and Bcl-XL downregulation. 966 22
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
Caspases are aspartate-specific cysteine proteases that play a pivotal role in drug-induced cell death. We designed RT-PCR assays to analyse the expression of CASP-3, CASP-4, CASP-6 and the long and short isoforms of CASP-2 genes in human cells. These genes heterogeneously coexpress in leukemic cell lines and bone marrow samples from patients with de novo acute myelogenous leukemia at diagnosis. Treatment of U937 and HL60 leukemic cells and HT29 colon carcinoma cells with the topoisomerase II inhibitor etoposide upregulates CASP-2 and CASP-3 genes in these cells before inducing their apoptosis. This effect of etoposide is not observed in K562 cells and bcl-2-transfected U937 cells which are less sensitive to drug-induced apoptosis. Nuclear run-on experiments demonstrate that etoposide increases CASP gene transcription in U937 cells, an effect that is prevented by
Bcl-2
overexpression. Upregulation of CASP genes is associated with an enhanced synthesis of related procaspases that precedes the appearance of apoptosis markers including
caspase-3
activation, poly(ADP-ribose) polymerase cleavage and internucleosomal DNA fragmentation. These results suggest that the ability of tumor cells to upregulate CASP-2 and CASP-3 genes in response to cytotoxic drugs could be predictive of their sensitivity to drug-induced apoptosis.
...
PMID:Upregulation of CASP genes in human tumor cells undergoing etoposide-induced apoptosis. 967 9
We examined whether apoptosis is involved in hypoxic cell death using primary cultures of rat cortical neurons and whether the cell death is associated with changes in
Bcl-2
and Bax expressions and activities of caspases. Hypoxic insult accelerates apoptosis, as shown by apoptotic nuclei and by chromatin degradation of internucleosomal fragments. This apoptotic process is accompanied by a rapid and sustained down-regulation of
Bcl-2
, whereas levels of Bax are unchanged. Furthermore, hypoxic insult activates sequentially caspase-1-like and
caspase-3
-like proteases, following down-regulation of
Bcl-2
expression. Peptide inhibitors of either caspase-1 or
caspase-3
protect against neuronal death, although they do not prevent hypoxia-induced down-regulation of
Bcl-2
. Furthermore, treatment of cortical neurons with either insulin-like growth factor-1 (IGF-1) or basic fibroblast growth factor (bFGF), growth factors which are implicated to prevent neuronal loss in ischemic brain, partly prevented neuronal death accompanied by inhibition of alterations in
Bcl-2
protein levels and
caspase-3
-like activities. These results suggest that hypoxia induces neuronal death by down-regulation of
Bcl-2
protein levels followed by sequential activation of the caspases, and the protection from neuronal cell death of these growth factors under hypoxic conditions derives at least partly from their capability to prevent down-regulation of the anti-apoptotic protein levels.
...
PMID:Roles of Bcl-2 and caspases in hypoxia-induced neuronal cell death: a possible neuroprotective mechanism of peptide growth factors. 968 76
Burkitt's lymphoma cells that vary in their phenotypic characteristics show significantly different degrees of susceptibility to radiation-induced apoptosis. Propensity to undergo apoptosis is reflected in the degradation of substrates such as DNA-dependent protein kinase but the status of bcl-2, c-myc and p53 has been uninformative. In this study, we have focused on 2 Epstein-Barr virus (EBV)-associated Burkitt's cell lines, one (WW2) susceptible and the other (BL29) resistant to etoposide-induced apoptosis. Differences in expression of BHRF1, an EBV gene that is homologous to the
Bcl-2
proto-oncogene and known to inhibit apoptosis, or changes in apoptosis inhibitory proteins (IAPs), did not appear to account for the difference in susceptibility in the 2 cell lines. Cytoplasmic extracts from etoposide-treated WW2 cells caused apoptotic changes in nuclei isolated from either BL29 or WW2 cells, whereas extracts from BL29 cells failed to do so. In addition, extracts from etoposide-treated WW2 cells degraded the catalytic subunit of DNA-dependent protein kinase (DNA-PKcs), an important indicator of apoptosis, but this protein was resistant to degradation by BL29 extracts. It appears likely that
caspase 3
(CPP32) is involved in this degradation since it was activated only in the apoptosis susceptible cells and the pattern of cleavage of DNA-PKcs was similar to that reported previously with recombinant
caspase 3
. As observed previously, addition of
caspase 3
to nuclei failed to induce morphological changes indicative of apoptosis, but addition of
caspase 3
to nuclei in the presence of extract from the resistant cells led to apoptotic changes. We conclude that resistance to apoptosis in BL29 cells is due to a failure of etoposide to activate upstream effectors of caspase activity.
...
PMID:Resistance to etoposide-induced apoptosis in a Burkitt's lymphoma cell line. 968 10
Taxol, 1-beta-D-arabinofuranosylcytosine (ara-C), and etoposide induce apoptosis in HL-60 cells that is blocked by overexpression of
Bcl-2
or Bcl-xL.A 60-amino acid "loop" domain of
Bcl-2
and Bcl-xL that contains phosphorylation sites is known to negatively regulate their antiapoptotic function. In the present studies, Taxol-, ara-C-, or etoposide-induced apoptosis was examined in HL-60/Bcl-2delta and HL-60/Bcl-xLdelta cells that express the loop-deletional mutant cDNA constructs p19Bcl-2delta32-80 and p18Bcl-xLdelta26-83, respectively. This was compared with control HL-60/neo cells as well as HL-60/
Bcl-2
and HL-60/Bcl-xL cells. The latter two cell lines overexpress full-length
Bcl-2
and Bcl-xL, respectively. Immunoblot analyses showed that HL-60/neo and HL-60/Bcl-2delta cells express similar levels of p26Bcl-2. In contrast, as compared with HL-60/neo, HL-60/Bcl-xLdelta cells expressed significantly lower levels of p26Bcl-2. p29Bcl-xL and p21Bax levels were similar in all cell types. Exposure to etoposide (50 microM) or ara-C (100 microM) for 4 h induced apoptosis in HL-60/neo cells, but not in HL-60/
Bcl-2
, HL-60/Bcl-xL, HL-60/Bcl-2delta, or HL-60/Bcl-xLdelta cells. In contrast, Taxol treatment (500 nM for 24 h) triggered the molecular cascade of apoptosis, represented by the cytosolic increase of cytochrome c and poly(ADP-ribose) polymerase or the DNA fragmentation factor cleavage activity of
caspase-3
in HL-60/neo cells as well as in HL-60/Bcl-xLdelta and HL-60/Bcl-2delta cells, but not in their counterparts overexpressing full-length
Bcl-2
and Bcl-xL. Equal amounts of p26Bcl-2 were coimmunoprecipitated with apoptosis protease-activating factor 1 (APAF-1) in HL-60/neo and HL-60/Bcl-2delta cells, whereas a markedly higher level of p26Bcl-2 coimmunoprecipitated with APAF-1 in HL-60/
Bcl-2
cells. In association with Taxol-induced apoptosis, the levels of
Bcl-2
that were coimmunoprecipitated with APAF-1 declined in HL-60/neo and HL-60/Bcl-2delta cells. This was not observed in HL-60/
Bcl-2
cells, in which Taxol-induced apoptosis was blocked. Previous studies have demonstrated that Taxol induces phosphorylation of
Bcl-2
in association with Taxol-induced apoptosis of HL-60/neo cells. Immunoblot analysis demonstrated a Taxol-induced mobility shift of
Bcl-2
but not p19Bcl-2delta. Taxol also increased [32P]Pi incorporation in p26Bcl-2, but not in p19Bcl-2delta or p18Bcl-xL. These findings indicate that the loop domain is necessary for the Taxol-induced mobility shift and phosphorylation of
Bcl-2
. Loop domain also seems to be necessary for the antiapoptotic effect of
Bcl-2
against Taxol-induced apoptosis but not ara-C- or etoposide-induced apoptosis.
...
PMID:"Loop" domain is necessary for taxol-induced mobility shift and phosphorylation of Bcl-2 as well as for inhibiting taxol-induced cytosolic accumulation of cytochrome c and apoptosis. 969 42
The role of the basal activity of the serine/threonine protein kinase, protein kinase C (PKC) in the regulation of anti-CD95-induced apoptosis in Jurkat T cells was investigated. The PKC-specific inhibitor GF 109203X and the proposed cPKC-specific inhibitor Go 6976, in a concentration-dependent manner, increased the percentage of cells undergoing apoptosis induced by anti-CD95 mAb as demonstrated by propidium iodide (PI) staining, TUNEL assay and DNA fragmentation by gel electrophoresis. Furthermore, Go 6976 and GF 109203X abrogated phorbol myristate acetate-induced inhibition of anti-CD95-induced apoptosis. To examine the molecular mechanism by which PKC modulates anti-CD95-induced apoptosis, the effects of Go 6976 on known effector and regulatory molecules of cell death were studied. Increased recruitment of cells undergoing apoptosis was associated with enhanced anti-CD95-induced proteolytic cleavage of the most receptor-proximal cysteine protease caspase-8, subsequent cleavage and activation of the machinery protease
caspase-3
, and cleavage of the caspase substrates DNA-dependent protein kinase catalytic subunit, poly-(ADP-ribose) polymerase and lamin B1. CD95 and FADD protein levels in Jurkat T cells were not altered by Go 6976 treatment. In addition, Go 6976 did not alter protein levels and subcellular distribution of the anti-apoptotic molecules
Bcl-2
and Bcl-xL. These data suggest indirectly that basal PKC activity acts at an early stage in the anti-CD95-induced caspase pathway to attenuate subsequent activation of downstream effector molecules and associated apoptosis in Jurkat T cells.
...
PMID:Inhibition of the protein kinase C pathway promotes anti-CD95-induced apoptosis in Jurkat T cells. 970 Oct 26
Polymorphonuclear leukocytes (PMN) isolated from the oral cavity of healthy human volunteers, spontaneously generated superoxide, nitric oxide (NO) and other reactive oxygen species (ROS) which exhibited strong luminol chemiluminescence (LCL). To understand the physiological roles of oral PMN (OPMN), biochemical properties of the cells were analyzed. Biochemical analysis revealed that OPMN were already primed under physiological conditions. Western blot analysis revealed that they strongly expressed the inducible type of NO synthase (NOS II) and exhibited the activity to catalyze tyrosine phosphorylation of various proteins including a 115 kDa protein (cbl product). OPMN also generated H2O2 and .OH by some superoxide dismutase (SOD)-sensitive mechanism and released myeloperoxidase (MPO). Kinetic analysis using specific inhibitors revealed that OCl- generated by OPMN was predominantly responsible for the enhanced LCL. During the incubation under standard culture conditions, OPMN underwent apoptosis which proceeded more rapidly than that of the circulating PMN (CPMN). Immunochemical analysis revealed that expression of apoptosis-related gene products, such as
Bcl-2
, Bcl-xL and Bax, was below detectable levels with both cell types. However,
caspase-3
but not caspase-1 was markedly activated in OPMN. These results indicate that the primed OPMN spontaneously generate ROS and play an important role in the defense mechanism in the oral cavity and that the generated ROS activate
caspase-3
thereby inducing apoptosis of the cells.
...
PMID:Biochemical properties of human oral polymorphonuclear leukocytes. 970 29
The requirement for caspases (ICE-like proteases) were investigated in mediating apoptosis of WEHI7.2 mouse lymphoma cells in response to two death inducers with different mechanisms of action, the glucocorticoid hormone dexamethasone (DX) and the calcium-ATPase inhibitor thapsigargin (TG). Apoptosis induction by these agents followed different kinetics, and was closely correlated with in vivo activation of
caspase-3
(CPP32/Yama/
Apopain
) and cleavage of the caspase target protein poly(ADP-ribose) polymerase (PARP). Caspase activation and PARP cleavage were inhibited by
Bcl-2
overexpression. Cell extracts from DX- and TG-treated cells cleaved the in vitro synthesized baculovirus p35 ICE-like protease target, producing 25 and 10 kDa fragments. p35 cleavage was inhibited by mutating the active site aspartic acid to alanine, and by a panel of protease inhibitors that inhibit
caspase-3
-like proteases, including iodoacetamide, N-ethylmaleimide, and Ac-DEVD-cho. Treatment of cells in vivo with two cell permeant peptide fluoromethylketone inhibitors of caspase activity, Z-VAD-fmk and Z-DEVD-fmk, inhibited DX- and TG-induced apoptotic nuclear changes and maintained plasma membrane integrity, whereas the cathepsin inhibitor, Z-FA-fmk, and two calpain inhibitors failed to inhibit apoptosis. An unexpected observation was that due to the delayed time course of DX-induced apoptosis, optimal preservation of plasma membrane integrity was achieved by adding caspase inhibitors beginning 8 h after DX addition. In summary, the findings indicate that two diverse apoptosis-inducing signals converge into a common
Bcl-2
-regulated pathway that leads to caspase activation and apoptosis.
...
PMID:Apoptosis induction by the glucocorticoid hormone dexamethasone and the calcium-ATPase inhibitor thapsigargin involves Bc1-2 regulated caspase activation. 970 90
Taxol and Taxotere propagate apoptosis in Jurkat T cells via molecular signals that coincide with the appearance of two distinct cell populations. Cell cycle arrest in G2-M phase and activation of cell cycle-dependent kinases begin within 2 h and extend to most cells by 16 h. Phosphorylation of
Bcl-2
also begins within 2 h and intensifies from 2-16 h. Cell cycle arrest, activation of mitotic kinases, and phosphorylation of
Bcl-2
coincided with the appearance of a population of metastable cells that accumulate YO-PRO-1 dye, are resistant to the caspase inhibitor carbobenzoxy-L-aspartyl-alpha-[(2,6-dichlorobenzoyl)oxy]methane, and have intact genomic DNA. Phosphorylation and deactivation of kinases that relay survival/mitogenesis signals in T cells begin after 8 h and are prominent by 12-16 h. Deactivated kinases include c-Raf-1, p44 extracellular receptor kinase, and the tyrosine kinases c-Lck and ZAP-70. Activation of Mr 40,000 and Mr 52,000 kinases is also prominent by 12-16 h. The modulation of all these kinases coincided with the activation of
caspase-3
at 12 h and the appearance of a population of apoptotic cells that accumulate YO-PRO-1, are susceptible to the caspase inhibitor carbobenzoxy-L-aspartyl-alpha-[(2,6-dichloro-benzoyl)oxy]methane, and contain fragmented genomic DNA. This distinctive apoptosis signaling pathway may help account for the superior cytotoxic efficacy of taxanes in certain types of cancer.
...
PMID:Taxanes propagate apoptosis via two cell populations with distinctive cytological and molecular traits. 971 85
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