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

A murine erythroleukemic cell line (1-2-3) which expresses only the temperature-sensitive mutant p53 gene (Ala-to-Val substitution at codon 135) was established. These cells showed typical characteristics of apoptosis, when they were cultured at 32 degrees C. In this process, p53 recovered the wild-type p53 function and the expression of the p21 (waf1/cip1/sdi1), cyclin G1 and gadd45 genes was increased. However, no significant changes were detected in the expression of the mdm2, bcl-2, bax, fas and fasl genes, suggesting the existence of other genes associated with apoptosis. Genes up-regulated by p53 were screened by the mRNA differential display method. One of the up-regulated genes was identified as the elongation factor 1 alpha (EF-1 alpha) gene. EF-1 alpha is also a microtubule-severing protein. Upon the temperature-shift, the cells developed the morphology and the localization of alpha-tubulin similar to those of the cells treated with vincristine, a drug that affects microtubules. The microtubule-severing associated with up-regulation of EF-1 alpha by p53 may be a cause of the cell death. On the other hand, the function of cyclin G1 is not so clear despite the fact that 1-2-3 cells showed a significant increase of the cyclin G1 gene during the early stage of apoptosis. The yeast two-hybrid system was used to identify cyclin G1-associated proteins. One is a cytochrome c (Cyt c) oxidase subunit II (COXII). Cyclin G1 and COXII were co-immunoprecipitated from an extract of human osteosarcoma cell line that expressed high levels of cyclin G1. COX activity was also increased by temperature-shift in this cell line. The pattern of changes in COX activity was closely reflected by the expression of the cyclin G1 gene. Cyclin G1 and COXII associate physically with each other in vivo and that activation of COXII by binding to cyclin G1 upregulated by p53 may be associated with apoptosis. These two new pathways, p53-EF-1 alpha-microtubule-severing (-distortion of cytoskeleton) and p53-cyclin G1-COXII (-CytC, ATP-caspase-3 activation), may cooperate to induce apoptosis in this cell line.
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PMID:The mechanisms of death of an erythroleukemic cell line by p53: involvement of the microtubule and mitochondria. 1019 36

The cyclooxygenase-2 (COX-2) gene encodes an inducible enzyme that converts arachidonic acid to prostaglandins and is up-regulated in colorectal neoplasms. Evidence indicates that COX-2 may regulate apoptosis and can influence the malignant phenotype. Non-steroidal anti-inflammatory drugs (NSAIDs) inhibit COX enzymes and induce apoptosis in colorectal cancer cell lines, which may contribute to their antitumor effects. To determine whether forced COX-2 expression modulates susceptibility to drug-induced apoptosis, HCT-15 colon carcinoma cells were stably transfected with the COX-2 cDNA, and two clones overexpressing COX-2 were isolated. Selective COX-2 (NS398) and nonselective (sulindac sulfide) COX inhibitors, as well as 5-fluorouracil (5-FU), induced apoptosis (terminal deoxynucleotidyl transferase-mediated nick end labeling in a dosage-dependent manner. Forced COX-2 expression significantly attenuated induction of apoptosis by all three of the drugs compared with parental HCT-15 cells. NSAIDs and 5-FU induced the mitochondrial release of cytochrome c as well as caspase-3 and -9 activation, and to a much lesser extent, caspase-8. COX-2-overexpressing cells showed reduced cytochrome c and caspase activation, relative to parental cells. A specific inhibitor of caspase-3 restored cell survival after drug treatment. COX-2 transfectants were found to overexpress the antiapoptotic Bcl-2 mRNA and protein relative to parental cells. In conclusion, forced COX-2 expression significantly attenuates apoptosis induction by NSAIDs and 5-FU through predominant inhibition of the cytochrome c-dependent apoptotic pathway. COX-2-mediated up-regulation of Bcl-2 suggests a potential mechanism for reduced apoptotic susceptibility.
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PMID:Cyclooxygenase-2 overexpression reduces apoptotic susceptibility by inhibiting the cytochrome c-dependent apoptotic pathway in human colon cancer cells. 1241 64

The level of differentiation could influence sensitivity of colonic epithelial cells to various stimuli. In our study, the effects of TNF-alpha, inhibitors of arachidonic acid (AA) metabolism (baicalein, BA; indomethacin, INDO; niflumic acid, NA; nordihydroguaiaretic acid, NDGA), and/or their combinations on undifferentiated or sodium butyrate (NaBt)-differentiated human colon adenocarcinoma HT-29 cells were compared. NaBt-treated cells became growth arrested (blocked in G0/G1 phase of the cell cycle), and showed down-regulated Bcl-xL and up-regulated Bak proteins and increased expression of cyclooxygenase-2 (COX-2) and 5-lipoxygenase (5-LOX). These cells were more perceptive to anti-proliferative and apoptotic effects of TNF-alpha. Both inhibitors of LOX (BA and NDGA) and COX (INDO and NA) in higher concentrations modulated cell cycle changes accompanying NaBt-induced differentiation and induced various level of cell death in undifferentiated and differentiated cells. Most important is our finding that TNF-alpha action on proliferation and cell death can be potentiated by co-treatment of cells with AA metabolism inhibitors, and that these effects were more significant in undifferentiated cells. TNF-alpha and INDO co-treatment was associated with accumulation of cells in G0/G1 cell cycle phase, increased reactive oxygen species production, and elevated caspase-3 activity. These results indicate the role of differentiation status in the sensitivity of HT-29 cells to the anti-proliferative and proapoptotic effects of TNF-alpha, AA metabolism inhibitors, and their combinations, and imply promising possibility for novel anti-cancer strategies.
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PMID:The effects of TNF-alpha and inhibitors of arachidonic acid metabolism on human colon HT-29 cells depend on differentiation status. 1500 23

Amyloid-beta peptide (Abeta) binding alcohol dehydrogenase (ABAD), an enzyme present in neuronal mitochondria, is a cofactor facilitating Abeta-induced cell stress. We hypothesized that ABAD provides a direct link between Abeta and cytotoxicity via mitochondrial oxidant stress. Neurons cultured from transgenic (Tg) mice with targeted overexpression of a mutant form of amyloid precursor protein and ABAD (Tg mAPP/ABAD) displayed spontaneous generation of hydrogen peroxide and superoxide anion, and decreased ATP, as well as subsequent release of cytochrome c from mitochondria and induction of caspase-3-like activity followed by DNA fragmentation and loss of cell viability. Generation of reactive oxygen species (ROS) was associated with dysfunction at the level of mitochondrial complex IV (cytochrome c oxidase, or COX). In neurons cultured from Tg mAPP/ABAD mice, COX activity was selectively decreased, and cyanide, an inhibitor of complex IV, exacerbated leakage of ROS, induction of caspase-3-like activity, and DNA fragmentation. In vivo, Tg mAPP/ABAD mice displayed reduced levels of brain ATP and COX activity, diminished glucose utilization, as well as electrophysiological abnormalities in hippocampal slices compared with Tg mAPP mice. In contrast, neither Tg ABAD mice nor nontransgenic (non-TG) littermates showed similar changes in ATP, COX activity, glucose utilization or electrophysiological properties. Each of the genotypes (Tg ABAD, Tg mAPP and Tg mAPP/ABAD mice, and non-TG littermates) displayed normal reproductive fitness, development and lifespan (1) These findings link ABAD-induced oxidant stress to critical aspects of Alzheimer's disease (AD)-associated cellular dysfunction, suggesting a pivotal role for this enzyme in the pathogenesis of AD.
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PMID:ABAD enhances Abeta-induced cell stress via mitochondrial dysfunction. 1566 36

Growing evidence indicates that inducible cyclooxygenase-2 (COX-2) is involved in the pathogenesis of inflammatory disorders and various types of cancer. Endothelial progenitor cells recruited from the bone marrow have been shown to be involved in the formation of new vessels in malignancies and discussed for being a key point in tumour progression and metastasis. However, until now, nothing is known about an interaction between COX and endothelial progenitor cells (EPC). Expression of COX-1 and COX-2 was detected by semiquantitative RT-PCR and Western blot. Proliferation kinetics, cell cycle distribution and rate of apoptosis were analysed by MTT test and FACS analysis. Further analyses revealed an implication of Akt phosphorylation and caspase-3 activation. Both COX-1 and COX-2 expression can be found in bone-marrow-derived endothelial progenitor cells in vitro. COX-2 inhibition leads to a significant reduction in proliferation of endothelial progenitor cells by an increase in apoptosis and cell cycle arrest. COX-2 inhibition leads further to an increased cleavage of caspase-3 protein and inversely to inhibition of Akt activation. Highly proliferating endothelial progenitor cells can be targeted by selective COX-2 inhibition in vitro. These results indicate that upcoming therapy strategies in cancer patients targeting COX-2 may be effective in inhibiting tumour vasculogenesis as well as angiogenic processes.
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PMID:Inhibition of cyclooxygenase (COX)-2 affects endothelial progenitor cell proliferation. 1689 39

Oxidative stress, resulting from excessive production of reactive oxygen species (ROS), is a pathological state that causes profound cellular damage and eventual death resulting from the overactivation of glutamate receptors, and the generation of nitric oxide, superoxide and hydrogen peroxide (H(2)O(2)). As such, H(2)O(2) represents an important model for studying the neuropathology of oxidative stress in a variety of CNS disorders. The effects of H(2)O(2) on the viability of post-natal cerebellar granule neurons (CGNs), the nature of the cell death involved and the potential protection by adenosine receptors against the damage were examined in the current study. Hydrogen peroxide (10-400 microM) reduced CGN viability in a concentration- and time-dependent manner. The addition of catalase (100 U/ml) prevented this effect, and the non-specific COX inhibitor aspirin (1 mM) also alleviated the damage. A combination of H(2)O(2) (5 microM) and Cu(2+) (0.5 mM) resulted in a significant damage that was not prevented by the hydroxyl radical scavenger mannitol (50 mM). The permeability transition pore blocker cyclosporin A, the caspase-3 inhibitor Z-DEVD-fmk (40 microM) and the PARP-1 inhibitor DPQ (10 microM) each significantly protected against peroxide damage. While the A(1) adenosine receptor agonist CPA and the A(2A) receptor antagonist ZM241385 (each at 100 nM) elicited protection, the A(1) adenosine receptor blocker DPCPX and the A(2A) receptor agonist CGS21680 (each at 100 nM) showed no effect. The data demonstrate that H(2)O(2) induced oxidative stress in CGNs, involving both apoptotic and necrotic death, and this can be ameliorated by A(1) receptor activation or A(2A) receptor blockade.
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PMID:Cell death in rat cerebellar granule neurons induced by hydrogen peroxide in vitro: mechanisms and protection by adenosine receptor ligands. 1718 58

Placental oxidative stress has been implicated in many complications of human pregnancy, including preterm delivery and preeclampsia. It is now appreciated that reactive oxygen species can induce a spectrum of changes, ranging from homeostatic induction of enzymes to apoptotic cell death. Little is known regarding the occurrence of placental oxidative stress in other species. We investigated markers of oxidative stress in the labyrinthine (LZ) and junctional (JZ) zones of the murine placenta across gestational age, and correlated these with expression of the cyclooxygenase enzymes COX-1 and COX-2, and apoptosis. We tested a causal link between the two by subjecting placental explants to hypoxia-reoxygenation (H/R) in vitro, a known stimulus for generation of oxidative stress. Western blotting demonstrated significant increases in the concentrations of hydroxynonenal (HNE), COX-1 and COX-2 with gestational age. Dual-labelling demonstrated co-localisation of HNE, and COX-1 and COX-2 within the trophoblast of the LZ, and glycogen cells of the JZ. An apoptotic index based on TUNEL-positivity demonstrated an increase with gestational age, and dual-labelling showed co-localisation of TUNEL labelling with HNE and active caspase-3 within the trophoblast of the LZ. H/R significantly increased oxidative stress, induction of COX-1 and COX-2, and the apoptotic index. Co-localisation demonstrated the increases in COX to be within the trophoblast of the LZ, and in particular the glycogen cells of the JZ. Apoptosis was restricted to the LZ. We speculate that the induction of COX enzymes is a physiological response to oxidative stress, and may play a role in initiating or augmenting parturition. Generation of oxidative stress may also play a role in influencing the growth trajectory of the placenta, and its component cell types. The mouse may provide an experimental genetic model in which to investigate these phenomena.
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PMID:Oxidative stress and the induction of cyclooxygenase enzymes and apoptosis in the murine placenta. 1722 4

Expression of cyclooxygenase-2 (COX-2) is involved in the chronic inflammation-related development of Barrett's adenocarcinoma and the use of selective COX-2 inhibitors (coxibs) might provide new chemoprevention strategy for Barrett's adenocarcinoma (BA). Despite an excellent gastrointestinal (GI) safety profile of coxibs, their use is limited because of the possible cardiovascular complications. The coupling of NSAIDs with a NO-donating moiety has led to the birth of a new class of anti-inflammatory drugs, called the COX-inhibiting nitric oxide donators (CINODs). The member of this group, NO-aspirin (NO-ASA) retains the anti-inflammatory properties of traditional aspirin (ASA), but the release of NO accounts for anti-thromboembolic effect and better GI safety profile. The role of NO-ASA in the prevention of Barrett's adenocarcinoma (BA) has not been studied so far. Therefore, the aim of the present study was: 1) to analyse the expression of COX-2 in the biopsies obtained from BE; 2) to compare the effect of NO-ASA with that of ASA on proliferation rate in Barrett''s adenocarcinoma cell line (OE-33 cells); 3) to determine the effect of both compounds on the apoptosis rate using FACS analysis and expression of 32-kDa procaspase-3 and active proapoptotic 20-kDa caspase-3 in OE-33 cell line. The expression of COX-2 was assessed in biopsies obtained from the Barrett's mucosa and normal squamous epithelial esophageal mucosa from 20 BE patients by RT-PCR and Western blot analysis, respectively. The BA cell line (OE-33) was incubated with NO-ASA or ASA (10-1000 microM). The cell proliferation and apoptosis rate was measured by BrdU and FACS-analysis, respectively. The expression of caspase-3 (active and inactive form) was analyzed by Western blot. In Barrett's mucosa a significant up-regulation of COX-2 was observed. Compared with traditional ASA, NO-ASA caused a significantly stronger induction of apoptosis (dose-dependently). Inhibition of cell proliferation in OE-33 cells observed under NO-ASA treatment was due to the apoptosis induction. The increase in apoptotic rate was accompanied by the upregulation of active 20-kDa caspase-3. At the highest concentration (1000 microM), a necrotic death of OE-33 cells was observed under NO-ASA treatment. We conclude that: NO-ASA caused induction of apoptosis in BA cell line and slight growth inhibition. These results indicate that this compound may represent a promising chemopreventive agent for Barrett's adenocarcinoma.
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PMID:NO-releasing aspirin exerts stronger growth inhibitory effect on Barrett's adenocarcinoma cells than traditional aspirin. 1724 51

Nitric oxide (NO) is a potent extracellular and intracellular physiological messenger. However, NO liberated in excessive amounts can be involved in macromolecular and mitochondrial damage in brain aging and in neurodegenerative disorders. The molecular mechanism of its neurotoxic action is not fully understood. Our previous data indicated involvement of NO in the release of arachidonic acid (AA), a substrate for cyclo- and lipoxygenases (COX and LOX, respectively). In this study we investigated biochemical processes leading to cell death evoked by an NO donor, sodium nitroprusside (SNP). We found that SNP decreased viability of pheochromocytoma (PC12) cells in a concentration- and time-dependent manner. SNP at 0.1 mM caused a significant increase of apoptosis-inducing factor (AIF) protein level in mitochondria. Under these conditions 80% of PC12 cells survived. The enhancement of mitochondrial AIF level might protect most of PC12 cells against death. However, NO released from 0.5 mM SNP induced massive cell death but had no effect on protein level and localization of AIF and cytochrome c. Caspase-3 activity and poly(ADP-ribose) polymerase-1 (PARP-1) protein levels were not changed. However, PARP activity significantly decreased in a time-dependent manner. Inhibition of both COX isoforms and of 12/15-LOX significantly lowered the SNP-evoked cell death. We conclude that AIF, cytochrome c and caspase-3 are not responsible for the NO-mediated cell death evoked by SNP. The data demonstrate that NO liberated in excess decreases PARP-1 activity. Our results indicate that COX(s) and LOX(s) are involved in PC12 cell death evoked by NO released from its donor, SNP.
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PMID:Molecular mechanism of PC12 cell death evoked by sodium nitroprusside, a nitric oxide donor. 1856 Jun 9

Mitochondrial dysfunction and associated apoptosis have been reported in the pathogenesis of neuron degeneration. The effects of eicosapentaenoic acid (EPA) and arachidonic acid (AA) on the mitochondrial membrane potential, mitochondrial biogenesis, and mitochondrial function of rat C6 glioma cells were determined in this study. Increased cytochrome c release and activated caspase-3 expression were determined in cells treated with >20 microM C(2) ceramide. There were significant repressive effects on ceramide-induced cell death with 25-100 microM EPA and 25 microM AA pretreatment. However, significantly increased membrane potentials were detected in cells pretreated with 25 and 50 microM EPA compared to ceramide-treated cells, but not in AA pretreatment groups. In cells pretreated with EPA, ATP production loss was prevented from ceramide-induced mitochondrial dysfunction. In mitochondrial biogenesis related assay, both EPA and AA enhanced peroxisome proliferator-activated receptor gamma-coactivator-1alpha (PGC-1alpha) and mitochondrial transcription factor A (Tfam) transcriptional activities. However, elevated PGC-1alpha transcriptional activities in groups pretreated with 25, 50, and 100 microM EPA and only in the 100 microM AA group were analyzed. The Tfam transcriptional activities were enhanced in groups pretreated with 25 and 50 microM EPA and AA. Increased NADH dehydrogenase subunit 6 (ND6) mRNA expression was determined in cells pretreated with 25 and 50 microM EPA and 25 microM AA. Elevated protein levels of Tfam, flavoprotein, and cytochrome oxidase subunit III (COX III) were determined in cells pretreated with 25 and 50 microM EPA. The EPA-provided a more protective effect than AA against ceramide-induced cell death, which might mainly be due to maintaining the membrane potential and sustaining the mitochondrial ATP production function. EPA has more potential to elevate mitochondrial biogenesis through enhanced PGC-1alpha, and Tfam transcriptional activities may provide partial protection against ceramide cytotoxicity.
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PMID:Functional modulation of mitochondria by eicosapentaenoic acid provides protection against ceramide toxicity to C6 glioma cells. 1992 18


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