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)

Apoptosis induced in rat hepatocytes by transforming growth factor beta1 (TGF-beta1) was accompanied by the activation of interleukin-1beta converting enzyme (ICE)-like proteases. Cell lysates were isolated at various times after TGF-beta1 treatment and analyzed for ICE and CPP32-like activity, using N-acetyl-Tyr-Val-Ala-Asp-7-amino-4-methylcoumarin (Ac-YVAD.AMC) and benzyloxycarbonyl-Asp-Glu-Val-Asp-7-amino-4-trifluoromethylcoumarin (Z-DEVD.AFC), respectively. CPP32-like but not ICE protease activity increased in a time dependent manner and preceded the onset of apoptosis. Kinetic studies in cell lysates indicated that more than one CPP32-like protease was being activated. This was confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE)/Western blotting of TGF-beta1-treated cells, which showed limited processing of CPP32 as shown by the appearance of the catalytically active p17 subunit. Loss of pro-Mch3alpha was also observed but the catalytically active p19 subunit was not detected. Staurosporine, which induced a much greater level of hepatocyte apoptosis, produced a concomitant increase in CPP32/Mch3alpha processing as shown by the appearance of the p17/p19 subunits and the corresponding increase in CPP32-like protease activity. Apoptosis, CPP32/Mch3alpha processing and the increase in CPP32-like protease activity induced by TGF-beta1 and staurosporine were abolished in hepatocytes pretreated with Z-Asp-Glu-Val-Asp (OMe) fluoromethylketone (Z-DEVD.FMK) or Z-Val-Ala-Asp (OMe) fluoromethylketone (Z-VAD.FMK). These peptide analogues were potent inhibitors of CPP32-like protease activity in lysates. Pretreatment of hepatocytes with cycloheximide also blocked TGF-beta1-induced apoptosis and the increase in CPP32-like activity. Unlike Z-VAD.FMK and Z-DEVD.FMK, cycloheximide did not inhibit CPP32-like protease activity in cell lysates. Thus, cycloheximide may block apoptosis by inhibiting the synthesis of a protein, which is involved in the upstream events responsible for the activation of the CPP32-like protease activity. Our studies have identified two of the CPP32-like proteases, namely CPP32 and Mch3alpha, which are activated during the execution phase of hepatocyte apoptosis.
 ...
PMID:Processing/activation of CPP32-like proteases is involved in transforming growth factor beta1-induced apoptosis in rat hepatocytes. 918 77

The effects of the non-tumor-promoting protein kinase C (PKC) activator bryostatin 1 and the PKC inhibitors staurosporine and UCN-01 were examined with respect to modulation of 1-[beta-D-arabinofuranosyl]cytosine (ara-C)-induced apoptosis in human myeloid leukemia cells (HL-60) overexpressing the antiapoptotic protein Bcl-2. HL-60/Bcl-2 cells displayed a 5-fold increase in Bcl-2 protein compared with empty-vector counter-parts (HL-60/pCEP4) but comparable levels of Bax, Mcl-1, and Bcl-xL. After exposure to an equimolar concentration of ara-C (10 microM for 6 hr), HL-60/Bcl-2 cells were significantly less susceptible to apoptosis, DNA fragmentation, and loss of clonogenicity than HL-60/pCEP4 cells. The protective effect of increased Bcl-2 expression was manifested by a failure of ara-C to induce activation/cleavage of the Yama protease (CPP32; caspase-3) and degradation of one of its substrates, poly(ADP-ribose)polymerase to an 85-kDa cleavage product. When HL-60/Bcl-2 cells were preincubated with bryostatin 1 (10 nM; 24 hr) or coincubated with either staurosporine (50 nM; 6 hr) or UCN-01 (300 nM; 6 hr) after a 1-hr preincubation, exposures that exerted minimal effects alone, ara-C-induced apoptosis and DNA fragmentation were restored to levels equivalent to, or greater than, those observed in empty-vector controls. These events were accompanied by restoration of the ability of ara-C to induce CPP32 cleavage and activation, poly(ADP-ribose) polymerase degradation, and inhibition of colony formation. Western analysis of Bcl-2 protein obtained from overexpressing cells treated with bryostatin 1, staurosporine, or UCN-01 revealed the appearance of a slowly migrating species and a general broadening of the protein band, effects that were insensitive to the protein synthesis inhibitor cycloheximide. Alterations in Bcl-2 protein mobility on sodium dodecyl sulfate-polyacrylamide gel electrophoresis were reversed by treatment of lysates with alkaline phosphatase or protein phosphatase 2A; actions of the latter were blocked by the specific phosphatase inhibitor okadaic acid. In vivo labeling studies of Bcl-2 protein demonstrated increased incorporation of [32PO4]orthophosphate in drug-treated cells. Last, phosphorylated Bcl-2 failed to display decreased binding to the proapoptotic protein Bax. Collectively, these findings indicate that bryostatin 1, which down-regulates PKC, and staurosporine and UCN-01, which directly inhibit the enzyme, circumvent resistance of Bcl-2-overexpressing leukemic cells to ara-C-induced apoptosis and activation of the protease cascade. They also raise the possibility that modulation of Bcl-2 phosphorylation status contributes to this effect.
 ...
PMID:Agents that down-regulate or inhibit protein kinase C circumvent resistance to 1-beta-D-arabinofuranosylcytosine-induced apoptosis in human leukemia cells that overexpress Bcl-2. 939 80

Angiotensin II (Ang II) importantly contributes to the pathobiology of atherosclerosis. Since endothelial injury is a key event early in the pathogenesis of atherosclerosis, we tested the hypothesis that Ang II may injure endothelial cells by activation of cellular suicide pathways leading to apoptosis. Human umbilical venous endothelial cells (HUVECs) were incubated with increasing doses of Ang II for 18 hours. Apoptosis of HUVECs was measured by ELISA specific for histone-associated DNA fragments and confirmed by DNA laddering and nuclear staining. Ang II dose-dependently induced apoptosis of HUVECs. Simultaneous blockade of both the AT1 and AT2 receptor prevented Ang II-induced apoptosis, whereas each individual receptor blocker alone was not effective. Selective agonistic stimulation of the AT2 receptor also dose-dependently induced apoptosis. Ang II-mediated as well as selective AT2 receptor stimulation-mediated apoptosis was associated with the activation of caspase-3, a central downstream effector of the caspase cascade executing the cell death program. Specific inhibition of caspase-3 activity abrogated Ang II-induced apoptosis. In addition, the NO donors sodium nitroprusside and S-nitrosopenicillamine completely inhibited Ang II-induced apoptosis and eliminated caspase-3 activity. Thus, Ang II induces apoptosis of HUVECs via activation of the caspase cascade, the central downstream effector arm executing the cell death program. NO completely abrogated Ang II-induced apoptosis by interfering with the activation of the caspase cascade.
 ...
PMID:Angiotensin II induces apoptosis of human endothelial cells. Protective effect of nitric oxide. 940 Mar 77

Cell shrinkage is a major characteristic of apoptosis, but the mechanism and role of this process in cell death are poorly understood. The primary factor that controls volume regulation in all cells is ions, and thus we have examined the movement of ions at the single cell level in lymphocytes during apoptosis. Activation of the death program with several stimuli that act through independent pathways to stimulate apoptosis results in a synchronous shift of cells from a normal cell size to a shrunken cell size. Only the shrunken cells exhibit DNA fragmentation and an approximate 4-fold elevation of caspase-3-like activity. Analysis of K+ and Na+ ion content of individual cells by flow cytometry revealed that the intracellular ionic strength of apoptotic cells decreased substantially from their non-shrunken counterparts. Additionally, we show apoptosis is enhanced under conditions where the intracellular K+ concentration is diminished and that apoptosis is inhibited when K+ efflux is prevented. These data show that the efflux of ions, primarily potassium, plays a necessary and perhaps a pivotal role in the cell death program.
 ...
PMID:A primary role for K+ and Na+ efflux in the activation of apoptosis. 940 53

Vascular remodeling in atherogenesis is marked not only by cellular proliferation and migration but is also impacted by apoptotic cell death. Extensive studies have focused on the signal transduction events leading to apoptosis. CPP32, a member of the caspase/interleukin-1 beta-converting enzyme (ICE) protease family, has emerged as a central player in several reports of apoptosis pathways. Vascular smooth muscle cells (SMC) undergo apoptosis after treatment with various stimuli, including nitric oxide (NO) donors, such as sodium nitroprusside (SNP, 0.1-1 mM). The aim of the present study was to evaluate the role of CPP32 in SNP-induced apoptosis of SMC. We isolated a rabbit CPP32 cDNA by using degenerate primers and polymerase chain reaction technique. The predicted protein encoded by this cDNA contains the conserved sequence (QACRG) necessary for covalent linkage to poly(ADP-ribose) polymerase (PARP) as well as the three amino acids responsible for substrate recognition and catalysis reported in other caspase members. Using a segment of this cDNA as a probe, we found no change of CPP32 mRNA in cultured arterial SMC before and after SNP treatment. We also measured the protease activity of CPP32 against a chromophore p-nitroaniline (pNA)-labeled substrate, DEVD-pNA. Our results showed a dose-dependent increase of CPP32 activity in SMC, with a maximal 10-fold increase after SNP treatment. Addition of a competitive CPP32 inhibitor, DEVD-CHO, produced a 50% reduction in maximal stimulation. Immunoblot analysis illustrated that SNP treatment induced proteolytic cleavage of CPP32 into its enzymatically active subunit p17 as well as the degradation of PARP into a 85-kDa fragment. We further demonstrated that incubation of cultured SMC with DEVD-CHO significantly reduced SNP-induced DNA fragmentation. DNA fragmentation analysis was carried out using several methods including a cell death detection enzyme-linked immunosorbent assay kit, in situ end labeling, and DNA electrophoresis in agarose gel. Our data indicate that CPP32 mRNA is constitutively expressed in rabbit SMC and activation of CPP32 protein has a pivotal role in SNP-induced SMC apoptosis.
 ...
PMID:Molecular characterization of rabbit CPP32 and its function in vascular smooth muscle cell apoptosis. 957 16

The aim of our study was to characterize the temporal relationship of apoptosis to regional myocardial ischemia and reperfusion and we aimed to determine the effect of ischemia and reperfusion on the distribution of the pro-apoptotic cysteine protease caspase-3 (CPP 32, apopain, Yama) in an in vivo rat model. Male Sprague-Dawley rats (250-400 g) were anesthetized with sodium pentobarbital (65 mg/kg, i.p.), the left external carotid artery was isolated to monitor arterial pressure and a left thoracotomy was performed. Regional myocardial ischemia was induced by occluding the left main coronary artery for 45 min. The heart was reperfused for 0, 60, 120 or 180 min. TUNEL staining of formalin-fixed, paraffin-embedded left ventricle, and DNA fragmentation analysis, showed that apoptosis occurred during 45 min of ischemia alone, but further developed during the 3-h reperfusion period. Immunohistochemical analysis of ischemic/reperfused left ventricle showed caspase-3 levels were substantially elevated and localized in the ischemic/reperfused region, and that caspase-3 co-localized to TUNEL positive myocytes. Therefore, regional myocardial ischemia serves as a stimulus for myocyte apoptosis, and this form of cell death progresses time-dependently after the onset of reperfusion. Our studies implicate caspase-3 to be involved in apoptotic cell death in ischemic/reperfused rat heart.
 ...
PMID:Co-localization of the cysteine protease caspase-3 with apoptotic myocytes after in vivo myocardial ischemia and reperfusion in the rat. 960 22

To clarify mechanisms of neuronal death in the postischemic brain, we examined whether astrocytes exposed to hypoxia/reoxygenation exert a neurotoxic effect, using a coculture system. Neurons cocultured with astrocytes subjected to hypoxia/reoxygenation underwent apoptotic cell death, the effect enhanced by a combination of interleukin-1beta with hypoxia. The synergistic neurotoxic activity of hypoxia and interleukin-1beta was dependent on de novo expression of inducible nitric oxide synthase (iNOS) and on nitric oxide (NO) production in astrocytes. Further analysis to determine the neurotoxic mechanism revealed decreased Bcl-2 and increased Bax expression together with caspase-3 activation in cortical neurons cocultured with NO-producing astrocytes. Inhibition of NO production in astrocytes by N(G)-monomethyl-L-arginine, an inhibitor of NOS, significantly inhibited neuronal death together with changes in Bcl-2 and Bax protein levels and in caspase-3-like activity. Moreover, treatment of neurons with a bax antisense oligonucleotide inhibited the caspase-3-like activation and neuronal death induced by an NO donor, sodium nitroprusside. These data suggest that NO produced by astrocytes after hypoxic insult induces apoptotic death of neurons through mechanisms involving the caspase-3 activation after down-regulation of Bcl-2 and up-regulation of Bax protein levels.
 ...
PMID:Involvement of Bcl-2 family and caspase-3-like protease in NO-mediated neuronal apoptosis. 975 Nov 92

Histone acetylation has a key role in transcriptional activation, whereas deacetylation of histones correlates with the transcriptional repression and silencing of genes. Genetic repression may have an important role in neuronal aging, atrophy and degenerative diseases. Our aim was to study how histone deacetylase inhibitors, trichostatin A (TSA) and sodium butyrate, affect the metabolism of cultured rat cerebellar granule neurons and mouse Neuro-2a neuroblastoma cells. Cultured cells were exposed to 1-3 microM TSA and 1-10 mM butyrate for 1-2 days. Both of these inhibitors induced a prominent neuronal apoptosis characterized by morphological changes as well as by the activation of caspase-3 protease and subsequent cleavage of poly(ADP-ribose) polymerase, one of the caspase-3 targets. Caspase-3 activities reached the highest level on the second day after treatment, higher in the proliferating neuroblastoma cells than in the cerebellar granule neurons. Caspase-3 activation and morphological changes were prevented by cycloheximide treatment. Histone deacetylase inhibitors increased the DNA-binding activities of AP1, CREB and NF-kappaB transcription factors. These observations show that an excessive level of histone acetylation induces a stress response and an apoptotic cell death in neuronal cells.
 ...
PMID:Neuronal apoptosis induced by histone deacetylase inhibitors. 979 19

We studied the molecular mechanisms of apoptosis in the prostate cancer cell line LNCaP and whether overexpression of caspase activity could force this cell line to undergo apoptosis. The inhibitor of phosphomevalonate decarboxylase, sodium phenylacetate, and the protein kinase inhibitor staurosporine induced (a) release of cytochrome c from the mitochondria to the cytosol; (b) reduction in mitochondrial transmembrane potential; (c) proteolytic processing of caspase-3 and -7 but not -2; (d) cleavage of the DEVD substrate and the death substrates poly(ADP-ribose) polymerase and DNA fragmentation factor; and (e) apoptosis. The panspecific inhibitor of caspase activation N-benzyloxycarbonyl-Val-Ala-Asp(OMe)-fluoromethylketone (z-VAD-FMK) prevented all of these events except release of mitochondrial cytochrome c into the cytosol. None of these apoptotic signaling events were elicited by staurosporine or sodium phenylacetate treatment of LNCaP-Bcl-2 cells that overexpress the oncoprotein Bcl-2. Because caspase-7 is activated in every model of apoptosis that we have characterized thus far, we wished to learn whether overexpression of this protease could directly cause apoptosis of LNCaP cells. By using a replication-defective adenovirus, overexpression of caspase-7 protein in both LNCaP and LNCaP-Bcl-2 cells was accompanied by induction of cleavage of the DEVD substrate and TUNEL. These studies have demonstrated that caspase-7 and -3 are critical mediators of apoptosis in LNCaP cells. Caspase-7 was proteolytically activated in every model of apoptosis that we have developed, and the overexpression of it induced apoptosis of LNCaP and LNCaP-Bcl-2 cells. Thus, adenoviral-mediated transfer of caspase-7 may offer a new effective approach for the treatment of prostate cancer.
 ...
PMID:Signaling pathway activated during apoptosis of the prostate cancer cell line LNCaP: overexpression of caspase-7 as a new gene therapy strategy for prostate cancer. 992 51

Nitric oxide (NO) produced in inflammatory lesions may play a major role in the destruction of oligodendrocytes in multiple sclerosis and experimental allergic encephalomyelitis. The transformed murine oligodendroglial line N20.1 is much more resistant than primary oligodendrocytes to killing by the NO generator S-nitroso-N-acetyl-DL-penicillamine (SNAP). This observation prompted investigation of the mechanisms leading to cell death in the N20.1 cells and comparison of SNAP with another NO donor, sodium nitroprusside (SNP). We observed that N20.1 cells were 30 times more sensitive to SNP than to SNAP. The specific NO scavenger 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (PTIO) protected against SNP only, not against SNAP. However, dithiothreitol protected against both SNAP and SNP, indicating that S-nitrosylation of cysteines plays a major role in the cytotoxicity of both NO donors. We did not observe any formation of peroxynitrite or increase of Ca2+ concentration with either SNAP or SNP, thus excluding their involvement in the mechanisms leading to N20.1 cell death. Based on two observations, (a) potentiation of the cytotoxic effect of SNP when coincubated with ferricyanide or ferrocyanide, but not sodium cyanide, and (b) protection by deferoxamine, an iron cyanide chelator, we conclude that the greater sensitivity of N20.1 cells to SNP compared with SNAP is due to synergism between NO released and the iron cyanide portion of SNP, with the cyanide accounting for very little of the cytotoxicity. Finally, SNP but not SNAP induces some apoptosis, as shown by DNA laddering and protection by a caspase-3 inhibitor. These results suggest that low levels of NO in combination with increased iron content lead to apoptotic cell death rather than the necrotic cell death seen with higher levels of NO generated by SNAP.
 ...
PMID:Synergism of nitric oxide and iron in killing the transformed murine oligodendrocyte cell line N20.1. 1003 76


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