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)

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.
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PMID:Biochemical properties of human oral polymorphonuclear leukocytes. 970 29

Tat proteins (trans-activating proteins) are present in all known lentiviruses and are early RNA binding proteins that regulate transcription. Tat from the human immunodeficiency virus type-1 is a protein comprising 86 amino acids and encoded by 2 exons. The first 72 amino acids are encoded by exon 1 and exhibit full trans-activating activity. The second exon encodes a 14-amino-acid C-terminal sequence that is not required for trans-activation but does contain an RGD motif, which is important in binding to alphavbeta3 and alpha5beta1 integrins. Tat has an unusual property for a transcription factor; it can be released and enter cells freely, yet still retain its activity, enabling it to up-regulate a number of genes. Tat also has an angiogenic effect; it is a potent growth factor for Kaposi sarcoma-derived spindle cells, and, separately, it has been shown to bind to a specific receptor, Flk-1/KDR, on vascular smooth muscle cells, as well as to integrin-like receptors present on rat skeletal muscle cells and the lymphocyte cell line H9. It appears that the basic domain of tat is important, not only for translocation but also for nuclear localisation and trans-activation of cellular genes. As such, targeting of tat protein or, more simply, the basic domain provides great scope for therapeutic intervention in HIV-1 infection. There is also opportunity for tat to be used as a molecular tool; the protein can be manipulated to deliver non-permeable compounds into cells, an approach that already has been employed using ovalbumin, beta-galactosidase, horseradish peroxidase, and caspase-3.
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PMID:HIV-1-trans-activating (Tat) protein: both a target and a tool in therapeutic approaches. 1053 42

Metallothionein (MT) is a low-molecular-weight, sulfhydryl-rich, metal-binding protein that can protect against the toxicity of cadmium, mercury, and copper. However, the role of MT in arsenic (As)-induced toxicity is less certain. To better define the ability of MT to modify As toxicity, MT-I/II knockout (MT-null) mice and the corresponding wild-type mice (WT) were exposed to arsenite [As(III)] or arsenate [As(V)] either through the drinking water for 48 weeks, or through repeated sc injections (5 days/week) for 15 weeks. Chronic As exposure increased tissue MT concentrations (2-5-fold) in the WT but not in MT-null mice. Arsenic by both routes produced damage to the liver (fatty infiltration, inflammation, and focal necrosis) and kidney (tubular cell vacuolization, inflammatory cell infiltration, and interstitial fibrosis) in both MT-null and WT mice. However, in MT-null mice, the pathological lesions were more frequent and severe when compared to WT mice. This was confirmed biochemically, in that, at the higher oral doses of As, blood urea nitrogen (BUN) levels were increased more in MT-null mice (60%) than in WT mice (30%). Chronic As exposures produced 2-10 fold elevation of serum interleukin-1beta, interleukin-6, and tumor necrosis factor-alpha levels, with greater increases seen by repeated injections than by oral exposure, and again, MT-null mice had higher serum cytokines than WT mice after As exposure. Repeated As injections also decreased hepatic glutathione (GSH) by 35%, but GSH-peroxidase and GSH-reductase were minimally affected. MT-null mice were more sensitive than WT mice to the effect of GSH depletion by As(V). Hepatic caspase-3 activity was increased (2-3-fold) in both WT and MT-null mice, indicative of apoptotic cell death. In summary, chronic inorganic As exposure produced injuries to multiple organs, and MT-null mice are generally more susceptible than WT mice to As-induced toxicity regardless of route of exposure, suggesting that MT could be a cellular factor in protecting against chronic As toxicity.
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PMID:Metallothionein-I/II null mice are more sensitive than wild-type mice to the hepatotoxic and nephrotoxic effects of chronic oral or injected inorganic arsenicals. 1082 79

We describe an enzyme-linked immunosorbent assay (ELISA) for quantifying relative amounts of active caspase 3 in apoptotic cells. Covalent modification of caspase 3 active sites with a biotinylated inhibitor differentiates active from latent caspases. Capture on an ELISA plate with an antibody specific for caspase 3 makes the assay specific for caspase 3. Detection is with horseradish peroxidase (HRP)-conjugated streptavidin that binds to the biotinylated inhibitor covalently bound to caspase 3. Using the assay we detected 6.6 ng active caspase 3 per 10(6) apoptotic staurosporine-treated Jurkat cells. Specificity of the assay for caspase 3 was demonstrated by lack of signal with purified caspases 2, 7, 8, and 10 that were modified by a biotinylated inhibitor. Specificity was also demonstrated by lack of signal with apoptotic MCF-7 cells which do not express caspase 3. The ability to discriminate between active and latent caspase 3 was shown by Western blotting with HRP-streptavidin and anti-caspase 3. Although latent caspase 3 was captured it was not covalently modified with the biotinylated inhibitor. The basic principle of using a covalent inhibitor to identify active enzymes and an antibody to differentiate between enzymes with similar activities has potential for quantifying active members of many classes of enzymes.
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PMID:Quantification of active caspase 3 in apoptotic cells. 1093 64

Although gastric cancer formation with H. pylori in Mongolian gerbils was recently reported, the same inoculation procedure did not result in cancer formation in other animals such as mice. Disturbed regulation of apoptosis and cell proliferation are known to link the multistep process of carcinogenesis. The present study is designed to examine the level of gastric epithelial cell apoptosis in Mongolian gerbils colonized with the H. pylori (Sydney strain: SS1) in comparison with that in mice. Mice (C57BL/6) and Mongolian gerbils were orally inoculated with SS1 and the stomachs were examined 9 and 18 months later. MPO activity increased persistently in gerbils, but increased transiently in mice. While the levels of DNA fragmentation, caspase-3 activity, and the number of TUNEL-positive cells increased significantly in mice, such parameters were attenuated in gerbils. On the other hand, the number of PCNA-positive cells increased after SS1 inoculation only in Mongolian gerbils, suggesting the enhancement of cell turnover in H. pylori-colonized gerbils. In conclusion, the SS1-induced increase in gastric mucosal apoptosis observed in mice was attenuated significantly in Mongolian gerbils, suggesting the causative role for the higher incidence of gastric carcinogenesis in this animal.
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PMID:Attenuated apoptosis in H. pylori-colonized gastric mucosa of Mongolian gerbils in comparison with mice. 1183 40

The heme enzyme myeloperoxidase (MPO) has recently been implicated in hydrogen peroxide H(2)O(2)-induced apoptosis of HL-60 human leukemia cells. The purpose of this study was to investigate the molecular mechanism(s) of MPO-mediated apoptosis, in particular caspase-3 activation, and to determine the effects of the antioxidants ascorbate and (dihydro)lipoic acid. Incubation of HL-60 cells (1 x 10(6) cells/ml media) with H(2)O(2) (0-200 microM) resulted in dose-dependent stimulation of caspase-3 activity, DNA fragmentation, and morphological changes associated with apoptosis. Caspase-3 activity, DNA fragmentation and apoptosis were maximal at approximately 50 microM H(2)O(2). Pre-incubation of the cells with the MPO-specific inhibitor 4-aminobenzoic acid hydrazide (ABAH) and the heme enzyme inhibitor 3-aminotriazole (100 microM each) resulted in complete and partial inhibition, respectively, of intracellular MPO, caspase-3 activity, and apoptosis following addition of 50 microM H(2)O(2). Enhancement of cellular antioxidant status by pre-incubation of the cells with dehydro-ascorbic acid and lipoic acid, which are reduced intracellularly to ascorbate and dihydrolipoic acid, respectively, afforded protection against caspase-3 activation and apoptosis following addition of H(2)O(2). Addition of high concentrations of H(2)O(2) (200 microM) to cells pre-incubated with lipoic acid, however, resulted in cytotoxicity. Overall, our data indicate that MPO-derived oxidants, rather than H(2)O(2) itself, are involved in caspase-3 activation and apoptosis in HL-60 cells, and the antioxidants ascorbate and (dihydro)lipoic acid inhibit caspase-3 activation and apoptosis in these cells, likely via scavenging the MPO-derived oxidants.
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PMID:Myeloperoxidase-dependent caspase-3 activation and apoptosis in HL-60 cells: protection by the antioxidants ascorbate and (dihydro)lipoic acid. 1198 55

We have previously proposed the horseradish peroxidase (HRP) and the non-toxic plant hormone indole-3-acetic acid (IAA) as a novel system for gene-directed enzyme/prodrug therapy (GDEPT). The cytotoxic potential of HRP/IAA GDEPT and the induction of a bystander effect were demonstrated in vitro under normoxic as well as hypoxic tumour conditions. To date, the chemical agents and the cellular targets involved in HRP/IAA-mediated toxicity have not been identified. In the present work, some of the molecular and morphological features of the cells treated with HRP/IAA gene therapy were analysed. Human T24 bladder carcinoma cells transiently transfected with the HRP cDNA and exposed to the prodrug IAA showed chromatin condensation, formation of apoptotic bodies, DNA fragmentation, and Annexin V binding. Similar effects were observed when the cells were incubated with the apoptotic agent cisplatin. Caspases appeared to be involved as effectors in HRP/IAA-mediated apoptosis, since treatment with a general caspase inhibitor decreased the fraction of cells with micronuclei (MN) by 30%, with fragmented DNA by 50%, and with condensed chromatin by 60%. However, very little degradation of one of the downstream targets of caspase-3, PARP, could be detected, and apoptosis alone did not appear to account for the killing levels measured with a clonogenic assay. The effect of HRP/IAA treatment on cell cycle progression was also investigated, and a rapid cytostatic effect, equally affecting all phases of the division cycle, was observed.
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PMID:Mechanisms of cytotoxicity induced by horseradish peroxidase/indole-3-acetic acid gene therapy. 1224 74

Human neuroblastoma cells, SH-SY5Y, contain relatively low levels of thioredoxin (Trx); thus, they serve favorably as a model for studying oxidative stress-induced apoptosis (Andoh, T., Chock, P. B., and Chiueh, C. C. (2001) J. Biol. Chem. 277, 9655-9660). When these neurotrophic cells were subjected to nonlethal 2-h serum deprivation, their neuronal nitric oxide synthase and Trx were up-regulated, and the cells became more tolerant of oxidative stress, indicating that NO may protect cells from serum deprivation-induced apoptosis. Here, the mechanism by which NO exerts its protective effects was investigated. Our results reveal that in SH-SY5Y cells, NO inhibits apoptosis through its ability to activate guanylate cyclase, which in turn activates the cGMP-dependent protein kinase (PKG). The activated PKG is required to protect cells from lipid peroxidation and apoptosis, to inhibit caspase-9 and caspase-3 activation, and to elevate the levels of Trx peroxidase-1 and Trx, which subsequently induces the expression of Bcl-2. Furthermore, active PKG promotes the elevation of c-Jun, phosphorylated MAPK/ERK1/2, and c-Myc, consistent with the notion that PKG enhances the expression of Trx through its c-Myc-, AP-1-, and PEA3-binding motifs. Elevation of Trx and Trx peroxidase-1 and Mn(II)-superoxide dismutase would reduce H(2)O(2) and O(2)(), respectively. Thus, the cytoprotective effect of NO in SH-SY5Y cells appears to proceed via the PKG-mediated pathway, and S-nitrosylation of caspases plays a minimal role.
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PMID:Cyclic GMP-dependent protein kinase regulates the expression of thioredoxin and thioredoxin peroxidase-1 during hormesis in response to oxidative stress-induced apoptosis. 1241 92

Apoptotic loss of parenchymal cells may lead to organ dysfunctions in critically ill patients with septic states. As an antioxidant, the protective effects of N-acetylcysteine (NAC) are documented in many experimental and clinical studies. In this experimental study, we investigated the role of chronically used NAC in septic lung injury on a cecal ligation and puncture (CLP) model. To evaluate this, 30 male Wistar rats were randomly divided into four groups as sham (n = 7), CLP (n = 8), sham + NAC (n = 7) and CLP + NAC (n = 8) groups. NAC was administered 150 mg kg(-1) day through intramuscular route beginning 6 h after the operations and lasting for a period of 1 week. One week later, histopathology and epithelial apoptosis were assessed by hematoxylin-eosin and immunohistochemically by M30 and caspase 3 staining to demonstrate septic lung injury. Additionally, lung tissue myeloperoxidase (MPO) activity, malondialdehyde (MDA), and nitrite/nitrate levels were measured. The MPO activity and MDA levels in lung homogenates were found to be increased in CLP group and the administration of NAC prevented their increase significantly (P < 0.05). However, there were no significant differences among the groups regarding nitrite/nitrate levels. The number of apoptotic cells was significantly lower in CLP+NAC group than CLP group, and this finding was supported by M30 and caspase 3 expression in lung (P < 0.05). Lung histopathology was also protected by NAC in CLP-induced sepsis. In conclusion, the chronic use of NAC inhibited MPO activity and lipid peroxidation, which resulted in reduction of apoptosis in lung in this CLP model. Because lung tissue nitrite/nitrate levels did not change significantly, organs other than the lungs may be responsible for producing the increased nitric oxide during sepsis. The chronic use of NAC needs further investigation for its possible antiapoptotic potential in septic states besides its documented antioxidant and antiinflammatory effects.
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PMID:The protective effect of N-acetylcysteine on apoptotic lung injury in cecal ligation and puncture-induced sepsis model. 1268 49

Mistletoe lectin-II, a major component of Korean mistletoe (Viscum album var. coloratum) induces apoptotic death in cancer cells. In this study, we demonstrated that lectin-II induced the generation of pro-oxidants and thus resulted in the apoptotic death of human myeloleukemic U937 cells. We observed that lectin-II-induced apoptotic death was inhibited by antioxidants including reduced glutathione (GSH), N-acetylcysteine (NAC), ebselen, mnTBP, catalase and pyrrolidine dithiocarbamate (PDTC). GSH and NAC also abolished the apoptotic DNA ladder pattern fragmentation of U937 cells after lectin-II stimulation. Obviously, lectin-II treatment of cells resulted in a remarkable generation of intracellular hydrogen peroxide (H2O2) as an early event, which was monitored fluorimetrically using scopoletin-horse radish peroxidase (HRP) assay and peroxide-sensitive fluorescent probe, DCF-DA. In addition, antioxidants inhibited the activation of c-Jun N-terminal kinase (JNK)/stress-activated protein kinase (SAPK) as well as cytosolic release of cytochrome c by mistletoe lectin-II. Moreover, lectin-II-induced activation of caspase-9 and 3-like protease and cleavage of poly(ADP-ribose) polymerase (PARP) were inhibited by pretreatment of cells with thiol antioxidants, GSH and NAC. Taken together, these results suggest that Korean mistletoe lectin-II is a strong inducer of pro-oxidant generation such as H2O2, which mediates the JNK/SAPK activation, cytochrome c release, activation of caspase-9 and caspase 3-like protease, and PARP cleavage in human myeloleukemic U937 cells.
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PMID:Involvement of hydrogen peroxide in mistletoe lectin-II-induced apoptosis of myeloleukemic U937 cells. 1285 Feb 39


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