Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P42574 (caspase-3)
45,978 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The administration of the H(2)O(2)-specific scavenger catalase attenuated the generation of apoptosis by the antitumor drugs etoposide, camptothecin, doxorubicin, and cisplatin in U-937 human promonocytic cells. By contrast, the antioxidant potentiated the generation of apoptosis by the inducers of the stress response, heat shock and cadmium, in this and other myeloid cell types. Catalase also increased the heat shock-provoked stimulation of caspase-3 and -9 activities, as well as the release of cytochrome c from mitochondria to the cytosol. The potentiation of cell death by catalase correlated with its capacity to inhibit the stress response, as demonstrated by the suppression of 70- or 27-kDa heat-shock protein expression and the inhibition of heat-shock transcription factor 1 binding activity. Conversely, the toxicity of catalase plus heat shock was attenuated when the cells were preconditioned with a soft heating, which elevated the 70-kDa heat-shock protein levels. By contrast with catalase, the antioxidants superoxide dismutase and probucol did not inhibit heat-shock protein expression or affect apoptosis in U-937 cells. Finally, it was observed that the antitumor drugs did not activate the stress response in U-937 cells and that catalase failed to inhibit HSP expression and to potentiate apoptosis in heat shock-treated RPMI 8866 lymphoblastic cells. Taken together, these results provide the first demonstration of a proapoptotic action of catalase, suggest that H(2)O(2) is a critical regulator of both apoptosis and the stress response, and corroborate the antiapoptotic action of heat-shock proteins in myeloid cells.
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PMID:Differential effects of catalase on apoptosis induction in human promonocytic cells. Relationships with heat-shock protein expression. 1260 65

(1) Cadmium is an extremely toxic metal commonly found in industrial workplaces, a food contaminant and a major component of cigarette smoke. Cadmium can severely damage several organs, including the brain. In this work, we have studied both the cadmium toxicity on rat cortical neurons in culture and the possible protective effect of serum. (2) Our results indicate that: (1) cadmium is taken up by the neurons in a dose and serum dependent way; (2) cadmium, at concentrations from 1 micro M or 10 micro M (depending on the absence or the presence of serum) up to 100 micro M, decreases the metabolic capacity, which was evaluated by the XTT (tetrazolium salt) test; (3) cadmium induces apoptosis and LDH (lactate dehydrogenase) release in a dose dependent way; (4) in a serum-free medium, the cadmium-induced apoptosis is accompanied by caspase-3 activation; (5) both the caspase-3 activation and the cadmium-induced apoptosis are reversed by N-acethyl-Asp-Glu-Val-Asp-aldehyde (Ac-DEVD-CHO), a selective caspase-3 inhibitor, indicating that the caspase-3 pathway is involved in cadmium-induced apoptosis in cortical neurons; and (6) the cadmium concentrations which produce caspase-3 activation do not modify the intracellular ATP levels; however, higher cadmium concentrations lead to both intracellular ATP depletion and ATP release, but do not increase the caspase-3 activity, indicating that cadmium also produces cellular death by necrosis. (3) These results suggest that cadmium induces either apoptosis or necrosis in rat cortical neurons, depending on the cadmium concentration.
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PMID:Apoptosis and necrosis: two distinct events induced by cadmium in cortical neurons in culture. 1264 92

Cadmium, a well-known environmental hazard, has caused serious health problems in humans and animals. Accumulating evidence suggests the cadmium toxicity is mediated by oxidative stress-induced cell death. However, the molecular signaling underlying cadmium-induced apoptosis remains unclear. In this study, we demonstrate here that cadmium induced mixed types of cell death including primary apoptosis (early apoptosis), secondary necrosis (late apoptosis), and necrosis in normal human lung cells, MRC-5, as revealed by chromatin condensation, phosphatidylserine (PS) externalization, and hypodiploid DNA content. The total apoptotic cells reached a plateau of around 40.0% after 24 h exposure of 100 microM cadmium. Pretreatment with Z-Val-Ala-Asp-fluoromethylketone (Z-VAD-fmk), a broad spectrum of caspase inhibitor, could not rescue apoptotic cells from cadmium toxicity. Coincidently, we failed to detect the activation of pro-caspase-3 and cleavage of PARP by immunoblot, which implies the apoptogenic activity of cadmium in MRC-5 cells is caspase-independent. JC-1 staining also indicated that mitochondrial depolarization is a prelude to cadmium-induced apoptosis, which was accompanied by a translocation of caspase-independent pro-apoptotic factor apoptosis-inducing factor (AIF) into the nucleus as revealed by the immunofluorescence assay. In summary, this study demonstrated for the first time that cadmium induced a caspase-independent apoptotic pathway through mitochondria-mediated AIF translocation into the nucleus.
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PMID:Mitochondria-mediated caspase-independent apoptosis induced by cadmium in normal human lung cells. 1270 96

The current study was undertaken to investigate the role of apoptosis in hydrazine induced hepatotoxicity. Hepatocytes were exposed to hydrazinium nitrate (HzN) at two doses (50 and 75 mM) for 2 h then placed in fresh HzN-free media and cultured for an additional 24 h. Post-exposure, cell viability was evaluated at several time points by lactate dehydrogenase (LDH) leakage and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reduction. Markers of apoptosis (mitochondrial membrane potential, annexin binding, DNA fragmentation, caspase activation, and cytochrome c release) were measured 24 h post-exposure. The viability data showed time dependent increase in LDH leakage at 75 mM of HzN, with only a slight increase at 50 mM. MTT reduction showed a decrease in mitochondrial activity at both doses immediately after the 2 h continuous exposure. However, MTT reduction returned to normal at 50 mM while at 75 mM, MTT reduction initially recovered but then deteriorated to approximately 50% of controls at 24 h post-exposure. Based on viability data, exposure to 50 mM HzN for 2 h is a marginally toxic dose while 75 mM is a significantly toxic dose. The results for apoptosis biomarkers showed a reduction in mitochondrial membrane potential, an increase in annexin binding, an increase in total caspase activity, moderate activation of caspase-3, and release of cytochrome c. However, the appearance of DNA fragmentation in HzN exposed cells was very low compared to positive controls (cadmium and cyclosporine). The possibility that HzN induces apoptosis without the involvement of DNA fragmentation can not be ruled out. The present results, overall, suggest that apoptosis may be a contributing factor in acute HzN toxicity.
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PMID:Involvement of apoptosis in hydrazine induced toxicity in rat primary hepatocytes. 1278 Dec 13

Cadmium is a potent teratogen in laboratory animals, causing exencephaly when administered at early stages of development. Due to its heterogenicity with respect to molecular targets, the mechanisms behind cadmium toxicity are not well understood. In the present study, C57BL/6 pregnant mice were treated with saline, cadmium, or zinc plus cadmium at 8 days post-coitus and studied 24 h after exposure. Cadmium induced significant DNA damage in the embryonic cells. Cadmium also induced embryonic growth retardation, as well as a significant upregulation of p53, p21, and Bax transcription levels. At the same time, there was a downregulation of Bcl-2, shifting the equilibrium Bcl-2/Bax toward the apoptotic pathway. There was an increase in apoptotically stained cells in the cadmium-treated embryos, and pro-caspase-3 was significantly activated. Zinc pretreatment maintained DNA damage at the control levels. It also prevented cadmium-induced effects on the expression levels of p53 and p21. The cadmium-induced decrease in Bcl-2 was inhibited, whereas the Bax levels were maintained closer to the control values. The Bad transcripts did not change at any experimental condition. Morphologically, zinc could maintain the embryological development, where apoptotic areas were as in the controls, and decrease por-caspase-3 activation. In summary, cadmium administered to pregnant mice increased primary DNA damage and activated the apoptotic pathway. These effects could be ameliorated by zinc pretreatment, and, because of that, it is possible that the mechanisms of cadmium-induced teratogenicity are related to zinc metabolism.
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PMID:Cadmium-induced changes in apoptotic gene expression levels and DNA damage in mouse embryos are blocked by zinc. 1291 12

Both heme oxygenase-1 (HO-1) and p21(WAF1/Cip1) (p21) are involved in the pathogenesis of human cancer and their functions are closely associated with apoptosis. However, how these two molecules regulate apoptosis in human gastric cancer is unknown. In this study, we studied how HO-1 and p21 were regulated in two gastric cancer cell lines, MKN-45 with wild p53 and MKN-28 with mutant p53. The cells were treated with hemin and cadmium to induce HO-1. The result showed that HO-1 protein was significantly induced by hemin and cadmium in both cells tested. Following the HO-1 expression, p21 level was also markedly induced. The cells with increased HO-1 and p21 showed obviously resistantance to apoptotic stimuli. The levels of HO-1 and p21 induced were significantly inhibited by p38 mitogen-activated protein kinase (p38 MAPK) inhibitor (SB203580) and extracellular-regulated kinase (ERK) inhibitor (PD098059). Parallel to decreased HO-1 and p21 expression, the kinase inhibitors also significantly attenuated the resistance of the cells to apoptosis. The elevated HO-1 and p21 was further found to be associated with increase activity of the nuclear NF-kappaB and the inhibition of NF-kappaB led to the block of their induction. The elevated HO-1 and p21 were also demonstrated to be related to increased cellular inhibitor of caspase inbitory protein-2 (c-IAP2) and decreased caspapse-3 activity. It was noted that the above changes observed were not different between MKN-45 and MKN-28 cells, suggesting the functions of HO-1 and p21 were irrespective of the status of p53. In conclusion, we demonstrate that the resistance to apoptosis in gastric cancer cells with elevated HO-1 and p21 is independent of p53 status in a p38 MAPK- and ERK-mediated pathway with elevated c-IAP2 and decreased caspase-3 activity and that this pathway is sensitive to the inhibition of NF-kappaB.
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PMID:Upregulation of heme oxygenase-1 and p21 confers resistance to apoptosis in human gastric cancer cells. 1464 39

The nitric oxide (NO) donor, O2-vinyl 1-(pyrrolidin-1-yl)diazen-1-ium-1,2-diolate (V-PYRRO/NO), is metabolized by P450 enzymes to release NO within the liver and is effective in protecting against hepatotoxicity of endotoxin and acetaminophen. This study examined the effects of V-PYRRO/NO on cadmium (Cd) hepatotoxicity in mice. Mice were given multiple injections of V-PYRRO/NO (10 mg/kg, s.c. at 2-h intervals) before and after a hepatotoxic dose of Cd (3.7 mg/kg Cd as CdCl2, i.p.). V-PYRRO/NO administration reduced Cd-induced hepatotoxicity as evidenced by reduced serum alanine aminotransferase activity, improved pathology, and reduced hepatic lipid peroxidation. The protection by V-PYRRO/NO was not mediated by altered Cd distribution to the liver or within hepatic subcellular fractions. Similar inductions of metallothionein, a metal-binding protein, were observed in mice receiving Cd alone or Cd plus V-PYRRO/NO. Real-time reverse transcription-polymerase chain reaction analysis revealed that V-PYRRO/NO administration suppressed the expression of inflammation-related genes such as macrophage inflammatory protein-2, CXC chemokine, thrombospondin-1, intracellular adhesion molecular-1, and interleukin-6. V-PYRRO/NO also suppressed the expression of acute phase protein genes and genes related to cell-death pathways, such as c-jun/AP-1, nuclear factor-kappaB, early response growth factor-1, heme oxygenase-1, caspase-3, growth arrest, and DNA-damaging protein-153. In summary, the liver-selective NO donor, V-PYRRO/NO, protects against Cd hepatotoxicity in mice. This protection is not mediated through altered distribution of Cd but may be related to reduced hepatic inflammation, reduced acute phase responses, and the suppression of cell-death-related components.
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PMID:The nitric oxide donor, O2-vinyl 1-(pyrrolidin-1-yl)diazen-1-ium-1,2-diolate (V-PYRRO/NO), protects against cadmium-induced hepatotoxicity in mice. 1501 May 1

Cadmium is a well-known carcinogenic and immunotoxic metal commonly found in cigarette smoke and industrial effluent. An altered intracellular calcium ([Ca(2+)](i)) level has been implicated in the pathophysiology of immune dysfunction. The present study was designed to determine the possible involvement of calcium (Ca(2+)) and mitogen-activated protein kinases (MAPKs) signaling pathways on cadmium-induced cell death in J774A.1 murine macrophage cells. Cadmium caused a low-amplitude [Ca(2+)](i) elevation at 20 microM and rapid and high-amplitude [Ca(2+)](i) elevation at 500 microM. Exposure to cadmium dose-dependently induced phosphorylation of c-Jun NH(2)-terminal kinase (JNK) and deactivated p38 MAPK. Use of the selective JNK inhibitor SP600125 suggested that activation of JNK is pro-apoptotic and pro-necrotic. Buffering of the calcium response with 1,2-bis-(2-aminophenoxy)-ethane-N,N,N',N'-tetraacetic acid tetrakis (acetoxy-methyl) ester (BAPTA-AM) and ethylene glycol-bis-(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA) completely blocked cadmium-induced apoptotic response. The pretreatment of cells with BAPTA-AM and EGTA suppressed the cadmium-induced cell injury, including growth arrest, mitochondrial activity impairment, and necrosis, and it also recovered the cadmium-altered JNK and p38 MAPK activity. Chelating [Ca(2+)](i) also reversed cadmium-induced hydrogen peroxide generation, suggesting that production of reactive oxygen species (ROS) is related to [Ca(2+)](i). The present study showed that cadmium induces a [Ca(2+)](i)-ROS-JNK-caspase-3 signaling pathway leading to apoptosis. Furthermore, cadmium-induced [Ca(2+)](i) regulates phosphorylation/dephosphorylation of JNK and p38, and it modulates signal transduction pathways to proliferation, mitochondrial activity, and necrosis.
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PMID:Calcium-mediated activation of c-Jun NH2-terminal kinase (JNK) and apoptosis in response to cadmium in murine macrophages. 1525 39

Cadmium (Cd) induces oxidative stress and apoptosis in trout hepatocytes. We therefore investigated the involvement of the mitochondrial pathway in the initiation of apoptosis and the possible role of oxidative stress in that process. This study demonstrates that hepatocyte exposure to Cd (2, 5 and 10 microM) triggers significant caspase-3, but also caspase-8 and -9 activation in a dose-dependent manner. Western-blot analysis of hepatocyte mitochondrial and cytosolic fractions revealed that cytochrome c (Cyt c) was released in the cytosol in a dose-dependent manner, whereas the pro-apoptotic protein Bax was redistributed to mitochondria after 24 and 48 h exposure. We also found that the expression of anti-apoptotic protein Bcl-xL, known to be regulated under mild oxidative stress to protect cells from apoptosis, did not change after 3 and 6 h exposure to Cd, then increased after 24 and 48 h exposure to 10 microM Cd. In the second part of this work, two antioxidant agents, 2,2,6,6-tetramethylpiperidinyl-1-oxyl (TEMPO) (100 microM) and N-acetylcysteine (NAC, 100 microM) were used to determine the involvement of reactive oxygen species (ROS) in Cd-induced apoptosis. Simultaneously exposing trout hepatocytes to Cd and TEMPO or NAC significantly reduced caspase-3 activation after 48 h and had a suppressive effect on caspase-8 and -9 also, mostly after 24 h. Lastly, the presence of either one of these antioxidants in the treatment medium also attenuated Cd-induced Cyt c release in cytosol and the level of Bax in the mitochondria after 24 and 48 h, while high Bcl-xL expression was observed. Taken together, these data clearly evidenced the key role of mitochondria in the cascade of events leading to trout hepatocyte apoptosis in response to Cd and the relationship that exists between oxidative stress and cell death.
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PMID:Cadmium-induced apoptosis through the mitochondrial pathway in rainbow trout hepatocytes: involvement of oxidative stress. 1527 30

Previous reports have demonstrated that cadmium (Cd) may induce cell death via apoptosis, but the mechanism responsible for cellular death is not clear. In this study, we investigated the signaling pathways implicated in Cd-induced apoptosis in lung epithelial fibroblast (WI 38) cells. Apoptotic features were observed using terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay, propidium iodide staining and DNA laddering. A treatment of cadmium caused the caspase-8-dependent Bid cleavage, the release of cytochrome c (Cyt c), activation of caspase-9 and -3, and PARP cleavage. A caspase-8 specific inhibitor prevented the Bid cleavage, caspase-3 activation and cell death. Alternatively, we observed that full-length Bax was cleaved into 18-kDa fragment (p18/Bax); this was initiated after 12 h and by 36 h the full-length Bax protein was totally cleaved to the p18/Bax, which caused a drastic release of Cyt c from mitochondria. The p18/Bax was detected exclusively in the mitochondrial fraction, and it originated from mitochondrial full-length Bax, but not from the cytosol full-length Bax. Cd also induced the activation of the mitochondrial 30-kDa small subunit of calpain that was preceded by Bax cleavage. Cd induced the upregulation of Bcl-2 and the degradation of p53 protein. N-acetyl cysteine effectively inhibited the Cd-induced DeltaPsim reduction, indicating ROS acts upstream of mitochondrial membrane depolarization. Taken together, our results suggest that Cd-induced apoptosis was thought to be mediated at least two pathways; caspase-dependent Bid cleavage, and the other is calpain-mediated mitochondrial Bax cleavage. Moreover, we found that the function of Bid and Bax was not dependent of Bcl-2, and that ROS can also contribute in the Cd-induced cell death.
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PMID:Cadmium induces apoptotic cell death in WI 38 cells via caspase-dependent Bid cleavage and calpain-mediated mitochondrial Bax cleavage by Bcl-2-independent pathway. 1545 Sep 50


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