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)

We have assessed amyloid beta protein (Abeta)-induced neurotoxicity, with and without added tunicamycin (TM), an inhibitor of N-glycosylation in the endoplasmic reticulum (ER), in rat organotypic hippocampal slice cultures (OHCs). In the rat OHCs cultured for 3 weeks, there was little neurotoxicity after treatment with Abeta(25-35) (25 microM) alone for 48 h. However, with TM alone, concentration-dependent neuronal death was observed at concentrations between 20 and 80 microg/mL. When amyloid-beta protein was combined with tunicamycin (Abeta+TM), cell death was more acute than with TM alone. Western blot analysis revealed that calpain activity and the active forms of caspase-12 and caspase-3 was increased after exposure to Abeta+TM as compared with exposure to TM alone. In contrast, the levels of glucose regulated protein (GRP)94, GRP78 and C/EBP homologous protein (CHOP) were not changed in the presence of Abeta. Abeta potentiation of TM neurotoxicity was reversibly blocked by S-allyl-L-cysteine (SAC), an organosulfur compound purified from aged garlic extract, and the L-type calcium channel blocker, nifedipine, in a restricted neuronal area of the OHCs. Simultaneously applied SAC also reversed the increases in calpain activity and the active forms of caspase-12 and caspase-3 by Abeta+TM with no change in the increased levels of GRP94, GRP78 and CHOP. These data indicate that Abeta facilitates the calpain-caspase-12-caspase-3 pathway, thus potentiating TM-induced neuronal death in the hippocampus.
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PMID:Amyloid beta-protein potentiates tunicamycin-induced neuronal death in organotypic hippocampal slice cultures. 1756 Jul 26

Hepatocyte apoptosis is an important feature of liver injury in hepatitis C virus (HCV) infection. However, the mechanism of apoptosis and consequences on disease progression in vivo have not been investigated fully in part due to the lack of adequate small animal models. In this study, transgenic (tg) mice were produced that express conditionally HCV structural proteins (core, E1, E2 and p7) in the liver following Cre-mediated DNA recombination. Using a novel Cre-estrogen receptor fusion protein (Cre-ER) induction strategy, tamoxifen was injected intraperitoneally (i.p.), which induced Cre nuclear translocation, transgene recombination and HCV protein expression in the liver. Hepatic expression of HCV core and envelope proteins resulted in increased hepatocyte apoptosis, detected by the TUNEL assay, between 7 and 33 days after induction. These results were confirmed by the presence of increased levels of apoptosis-associated cytokeratin 18 (CK-18) in the sera of the same animals. The presence of cleaved caspase-3 and elevated levels of CHOP/GADD153 in the liver suggests an endoplasmic reticulum (ER) stress-associated apoptosis mechanism. This study suggests an in vivo correlation between HCV structural protein expression, ER stress and hepatocyte apoptosis, implicating a potentially important mechanism of HCV pathogenesis.
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PMID:Cre-estrogen receptor-mediated hepatitis C virus structural protein expression in mice. 1762 8

Crude extracts of Euchresta formosana radix (EFR) have previously been observed to induce the suppression of liver cancer Hep3B cell growth and induce apoptosis in response to overexpression of reactive oxygen species, GADD153, Bax and caspase-3, and to decrease the levels of mitochondrial membrane potential in vitro. In this study, the effect of EFR on cell migration and invasion by the human liver hepatocellular carcinoma (HCC) cell line Hep3B was examined. Hep3B cells treated in vitro with EFR migrated and invaded less than cells treated with phosphate-buffered saline (PBS) as a control. EFR inhibited migration and invasion by down-regulating the production of RhoA and ROCK1, FAK, and matrix metalloproteinase-1, -2, -9 and -10 relative to PBS only. These results show that EFR inhibits invasion and migration by liver cancer cells by down-regulating proteins associated with these processes, resulting in reduced metastasis. Thus, EFR should be considered as a possible therapeutic agent for inhibiting primary tumor growth and preventing metastasis.
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PMID:Crude extracts of Euchresta formosana radix inhibit invasion and migration of human hepatocellular carcinoma cells. 1769 28

Farnesol (FOH) and other isoprenoid alcohols induce apoptosis in various carcinoma cells and inhibit tumorigenesis in several in vivo models. However, the mechanisms by which they mediate their effects are not yet fully understood. In this study, we show that FOH is an effective inducer of apoptosis in several lung carcinoma cells, including H460. This induction is associated with activation of several caspases and cleavage of poly(ADP-ribose) polymerase (PARP). To obtain insight into the mechanism involved in FOH-induced apoptosis, we compared the gene expression profiles of FOH-treated and control H460 cells by microarray analysis. This analysis revealed that many genes implicated in endoplasmic reticulum (ER) stress signaling, including ATF3, DDIT3, HERPUD1, HSPA5, XBP1, PDIA4, and PHLDA1, were highly up-regulated within 4 h of FOH treatment, suggesting that FOH-induced apoptosis involves an ER stress response. This was supported by observations showing that treatment with FOH induces splicing of XBP1 mRNA and phosphorylation of eIF2alpha. FOH induces activation of several mitogen-activated protein kinase (MAPK) pathways, including p38, MAPK/extracellular signal-regulated kinase (ERK) kinase (MEK)-ERK, and c-jun NH2-terminal kinase (JNK). Inhibition of MEK1/2 by U0126 inhibited the induction of ER stress response genes. In addition, knockdown of the MEK1/2 and JNK1/2 expression by short interfering RNA (siRNA) effectively inhibited the cleavage of caspase-3 and PARP and apoptosis induced by FOH. However, only MEK1/2 siRNAs inhibited the induction of ER stress-related genes, XBP1 mRNA splicing, and eIF2alpha phosphorylation. Our results show that FOH-induced apoptosis is coupled to ER stress and that activation of MEK1/2 is an early upstream event in the FOH-induced ER stress signaling cascade.
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PMID:Farnesol-induced apoptosis in human lung carcinoma cells is coupled to the endoplasmic reticulum stress response. 1769

Alzheimer's disease (AD) is the major cause of dementia, accounting for 50% to 70% of the late-onset patients, with 17 to 20 million affected. It is characterized by neurofibrillary tangles, neuronal loss, and amyloid plaques in tissues of the cortex, hippocampus, and amygdala. Apoptosis or programmed cell death appears in the progression of AD. In this study, we investigated the gene expression of 14 apoptotic genes (E2F1, p21/WAF, ICE-LAP3, Fas Antigen, CPP-32, GADD153, ICE-beta, c-Fos, c-Jun, Bax-alpha, Bcl-2, Bcl-(x)L, BAK, and p53) in 5 normal and 6 AD human hippocampal tissues, using reverse transcription-polymerase chain reaction. Our results show an upregulation of gene expression in AD patients for c-Fos and BAK. ICE-beta, c-Jun, Bax-alpha, Bcl-x(L), p53, and GADD153 were found to be upregulated in some AD samples but were not detected or downregulated in other AD or normal samples. No gene expression was found for E2F1 , p21/WAF, ICE-LAP3, Fas Antigen, CPP32, or Bcl-2. These results indicate significant increases in c-Fos , c-Jun, and Bak; therefore, we suggest that these genes may be critical in the apoptotic cascades of AD.
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PMID:Apoptotic gene expression in Alzheimer's disease hippocampal tissue. 1771 63

Berberine, an isoquinoline alkaloid, has been shown to possess anticancer properties in some cancer cell lines. Here, we report that in vitro treatment of cervical cancer Ca Ski cells with berberine decreased the percentage of viable Ca Ski cells in a dose-dependent and time-dependent manner. Berberine enhanced the apoptosis of Ca Ski cells with the induction of a higher ratio of p53 and Bax/Bcl-2 proteins, increased levels of reactive oxygen species (ROS) and Ca2+, disruption of the mitochondrial membrane potential, and promotion of caspase-3 activity. In CaSki cells pretreated with the pan-caspase inhibitor zVAD-fmk, the berberine-induced caspase-3 activity and apoptosis were significantly blocked as confirmed by flow cytometric analysis. Western blot also showed that berberine induced the expression of GADD153, a transcription factor involved in apoptosis. Thus berberine increased ROS levels leading to endoplasmic reticulum (ER) stress based on the increase of GADD153 and shown by Ca2+ release from the ER. When the Ca Ski cells were pretreated with catalase, GADD153 production was abrogated and apoptosis was significantly reduced.
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PMID:GADD153 mediates berberine-induced apoptosis in human cervical cancer Ca ski cells. 1797 84

Several causal missense mutations in protein kinase C gamma (gamma PKC) gene have been found in spinocerebellar ataxia type 14 (SCA14), an autosomal dominant neurodegenerative disease. We previously demonstrated that mutant gamma PKC found in SCA14 is susceptible to two types of aggregation, cytoplasmic dot-like and perinuclear massive aggregation, and causes cell death in Chinese hamster ovary cells. Long-term time-lapse imaging revealed that firstly accumulated dot-like aggregation of mutant gamma PKC-green fluorescent protein (GFP) gradually formed perinuclear massive aggregations, followed by cell death. However, it remains unclear how aggregate formation of mutant gamma PKC causes cell death. In the present study, we examined whether these mutant aggregations affect the ubiquitin-proteasome system (UPS) and endoplasmic reticular (ER) stress. Two mutant gamma PKC-GFPs (S119P and G128D) were strongly ubiquitinated, and dot-like aggregations of these mutants were ubiquitin-positive and colocalized with proteasome 20S. Furthermore, proteasome activity in cells with aggregates, especially massive ones, was significantly decreased. Aggregate formation of mutant gamma PKC-GFP induced phosphorylation of PERK (PKR-like ER kinase) and nuclear expression of CHOP (C/EBP homologous protein), hallmarks of ER stress and subsequently activated caspase-3. These results indicate that aggregate formation of mutant gamma PKC found in SCA14 impairs UPS and induces ER stress, leading to apoptotic cell death.
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PMID:Aggregate formation of mutant protein kinase C gamma found in spinocerebellar ataxia type 14 impairs ubiquitin-proteasome system and induces endoplasmic reticulum stress. 1800 63

Recently, the endoplasmic reticulum (ER) has been disclosed as subcellular target reactive to ischaemia/reperfusion and possibly influenced by hypothermic machine preservation. Here, the respective role of perfusate, perfusion itself, and the effect of continuous oxygenation to trigger ER-stress in the graft should be investigated. Livers were retrieved 30 min after cardiac arrest of male Wistar rats and preserved by cold storage (CS) in histidine-tryptophan-ketoglutarate (HTK) for 18 h at 4 degrees C. Other organs were subjected to aerobic conditions either by oxygenated machine perfusion with HTK (MP-HTK) or Belzer solution (MP-Belzer) at 4 degrees C or by venous insufflation of gaseous oxygen during cold storage (VSOP). Viability of livers was evaluated upon reperfusion in vitro according to previously validated techniques for 120 min at 37 degrees C. Oxygenation during preservation (MP-HTK, MP-Belzer or VSOP) concordantly improved functional recovery (bile flow, ammonia clearance), reduced parenchymal enzyme leakage and histological signs of necrosis and significantly attenuated mitochondrial induction of apoptosis (cleavage of caspase 9) compared to CS. However, MP with either medium produced about 500% elevated protein expression of CHOP/GADD153, suggesting pro-apoptotic ER-stress responses, paralleled by a significant elevation of caspase-12 enzyme activity compared to CS or VSOP. Although MP also promoted a slight (20%) induction of the cytoprotective ER-protein Bax inhibitor protein (BI-1), prevailing of proapoptotic reactions was seen by increased cleavage of caspase-3 and poly (ADP-Ribase)-polymerase (PARP) in both MP-groups. Endoplasmic stress activation is conjectured a specific side effect of long-term machine preservation irrespective of the medium, actually promoting cellular apoptosis via activation of caspase-12. The simple insufflation of gaseous O2 may be considered a feasible alternative, apparently indifferent to the endoplasmic reticulum.
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PMID:Role of perfusion medium, oxygen and rheology for endoplasmic reticulum stress-induced cell death after hypothermic machine preservation of the liver. 1800 84

In order to elucidate underlying mechanism of cell death pathways in neuronal cells in humans, we studied responsible pathways involved in the endoplasmic reticulum (ER) stress-induced cell death in neuroblastoma cells, SK-N-SH and its neuroblast-type subclone SH-SY5Y cells. A time-dependent induction of ER chaperons, glucose regulated protein (GRP)78 and GRP94, was observed after treatment with tunicamycin (TM), and cell death was also induced concomitantly in both cells. Although the pro-caspase-12-like protein was defined in both cells, a decrease in the protein was observed in only SH-SY5Y cells after exposure to TM. In contrast, pro-caspase-4 was detected in only SK-N-SH cells, and the cleaved-form was induced by the treatment with TM. A caspase-4 inhibitor, Z-LEVD-FMK attenuated TM-induced cell death in SK-N-SH cells. Calpain- and caspase-3-mediated proteolysis of alpha II-spectrin was also increased after the treatment with TM in both cells. A calpain inhibitor, calpeptin, repressed TM-induced cell death in only SK-N-SH cells. GADD153/C/EBP homologous protein (CHOP) was significantly induced after exposure to TM in only SH-SY5Y cells and RNA interference to GADD153/CHOP repressed TM-induced cell death. These results demonstrate that induction of GADD153/CHOP plays a pivotal role in mechanism of ER stress-induced cell death in SH-SY5Y cells, on the other hand, cleavage of pro-caspase-4 by activation of calpain play a crucial role in SK-N-SH cells. It is also suggested that the relevance of caspase-4 to ER stress is cell-specific even between human-origin cell lines.
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PMID:Distinct mechanism of cell death is responsible for tunicamycin-induced ER stress in SK-N-SH and SH-SY5Y cells. 1802 41

Obstructive sleep apnea is associated with neural injury and dysfunction. Hypoxia/reoxygenation exposures, modeling sleep apnea, injure select populations of neurons, including hypoglossal motoneurons. The mechanisms underlying this motoneuron injury are not understood. We hypothesize that endoplasmic reticulum injury contributes to motoneuron demise. Hypoxia/reoxygenation exposures across 8 weeks in adult mice upregulated the unfolded protein response as evidenced by increased phosphorylation of PERK [PKR-like endoplasmic reticulum (ER) kinase] in facial and hypoglossal motoneurons and persistent upregulation of CCAAT/enhancer-binding protein-homologous protein (CHOP)/growth arrest and DNA damage-inducible protein (GADD153) with nuclear translocation. Long-term hypoxia/reoxygenation also resulted in cleavage and nuclear translocation of caspase-7 and caspase-3 in hypoglossal and facial motoneurons. In contrast, occulomotor and trigeminal motoneurons showed persistent phosphorylation of eIF-2a across hypoxia/reoxygenation, without activations of CHOP/GADD153 or either caspase. Ultrastructural analysis of rough ER in hypoglossal motoneurons revealed hypoxia/reoxygenation-induced luminal swelling and ribosomal detachment. Protection of eIF-2alpha phosphorylation with systemically administered salubrinal throughout hypoxia/reoxygenation exposure prevented CHOP/GADD153 activation in susceptible motoneurons. Collectively, this work provides evidence that long-term exposure to hypoxia/reoxygenation events, modeling sleep apnea, results in significant endoplasmic reticulum injury in select upper airway motoneurons. Augmentation of eIF-2a phosphorylation minimizes motoneuronal injury in this model. It is anticipated that obstructive sleep apnea results in endoplasmic reticulum injury involving motoneurons, whereas a critical balance of phosphorylated eIF-2a should minimize motoneuronal injury in obstructive sleep apnea.
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PMID:Eif-2a protects brainstem motoneurons in a murine model of sleep apnea. 1830 50


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