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)

Affinity labeling showed that active caspases with molecular masses of 20 kDa, 19 kDa, and 17 kDa were formed upon treatment of human leukemia U937 cells with GGO. These caspases are quite similar to those activated by treatments with other apoptosis-inducers, such as VP16 and camptothecin, suggesting that similar caspases, such as caspases 3 and 6, are activated during apoptosis in U937 cells that is induced by a variety of apoptosis-inducing stimuli. An inhibitor of caspases, Z-Asp-CH2DCB, inhibited DNA fragmentation in response to GGO in vivo by blocking the cleavage of 20-kDa to 17-kDa peptides. This cleavage is catalyzed by caspase 3 itself or by a caspase-3-like protease. In contrast, other inhibitors of caspases such as Z-DEVD-FMK and Z-VAD-FMK, inhibited the processing of the caspase 3 precursor p32 to 20-kDa and 17-kDa peptides, a result which suggests that these inhibitors inhibited other upstream caspases. Treatment of U937 cells with GGO resulted in the release of cytochrome c from mitochondria prior to DNA fragmentation and the release of cytochrome c was inhibited by Zn2+ ions and by a chelator of Ca2+ ions but not by inhibitors of caspases such as Z-Asp-CH2DCB or Z-VAD-FMK. These results suggest that intracellular free Ca2+ ions, and some caspases that are inhibited by Zn2+ ions, but not by Z-Asp-CH2DCB or Z-VAD-FMK are necessary for the release of cytochrome c that is caused by the treatment with GGO.
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PMID:Analysis of caspases that are activated during apoptosis in leukemia U937 cells in response to geranylgeraniol. 1069 11

We have previously reported the activation of procalpain mu (precursor for low-calcium-requiring calpain) in apoptotic cells using a cleavage-site-directed antibody specific to active calpain [Kikuchi, H. and Imajoh-Ohmi, S. (1995) Cell Death Differ. 2, 195-199]. In this study, calpastatin, the endogenous inhibitor protein for calpain, was cleaved to a 90-kDa polypeptide during apoptosis in human Jurkat T cells. The limited proteolysis of calpastatin preceded the autolytic activation of procalpain. Inhibitors for caspases rescued the cells from apoptosis and simultaneously inhibited the cleavage of calpastatin. The full-length recombinant calpastatin was also cleaved by caspase-3 or caspase-7 at Asp-233 into the same size fragment. Cys-241 was also targeted by these caspases in vitro but not in apoptotic cells. Caspase-digested calpastatin lost its amino-terminal inhibitory unit, and inhibited three moles of calpain per mole. Our findings suggest that caspases trigger the decontrol of calpain activity suppression by degrading calpastatin.
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PMID:Caspases cleave the amino-terminal calpain inhibitory unit of calpastatin during apoptosis in human Jurkat T cells. 1073 97

Axonal injury is a feature of traumatic brain injury (TBI) contributing to both morbidity and mortality. The traumatic axon injury (TAI) results from focal perturbations of the axolemma, allowing for calcium influx triggering local intraaxonal cytoskeletal and mitochondrial damage. This mitochondrial damage has been posited to cause local bioenergetic failure, leading to axonal failure and disconnection; however, this mitochondrial damage may also lead to the release of cytochrome c (cyto-c), which then activates caspases with significant adverse intraaxonal consequences. In the current communication, we examine this possibility. Rats were subjected to TBI, perfused with aldehydes at 15-360 min after injury, and processed for light microscopic (LM) and electron microscopic (EM) single-labeling immunohistochemistry to detect extramitochondrially localized cytochrome c (cyto-c) and the signature protein of caspase-3 activation (120 kDa breakdown product of alpha-spectrin) in TAI. Combinations of double-labeling fluorescent immunohistochemistry (D-FIHC) were also used to demonstrate colocalization of calpain activation with cyto-c release and caspase-3-induction. In foci of TAI qualitative-quantitative LM demonstrated a parallel, significant increase in cyto-c release and caspase-3 activation over time after injury. EM analysis demonstrated that cyto-c and caspase-3 immunoreactivity were associated with mitochondrial swelling-disruption in sites of TAI. Furthermore, D-IFHC revealed a colocalization of calpain activation, cyto-c release, and caspase-3 induction in these foci, which also revealed progressive TAI. The results demonstrate that cyto-c and caspase-3 participate in the terminal processes of TAI. This suggests that those factors that play a role in the apoptosis in the neuronal soma are also major contributors to the demise of the axonal appendage.
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PMID:Cytochrome c release and caspase activation in traumatic axonal injury. 1075 34

Calcium overload is suggested to play a fundamental role in the process of rod apoptosis in chemical-induced and inherited retinal degenerations. However, this hypothesis has not been tested directly. We developed an in vitro model utilizing isolated rat retinas to determine the mechanisms underlying Ca(2+)- and/or Pb(2+)-induced retinal degeneration. Confocal microscopy, histological, and biochemical studies established that the elevated [Ca(2+)] and/or [Pb(2+)] were localized to photoreceptors and produced rod-selective apoptosis. Ca(2+) and/or Pb(2+) induced mitochondrial depolarization, swelling, and cytochrome c release. Subsequently caspase-9 and caspase-3 were sequentially activated. Caspase-7 and caspase-8 were not activated. The effects of Ca(2+) and Pb(2+) were additive and blocked completely by the mitochondrial permeability transition pore (PTP) inhibitor cyclosporin A, whereas the calcineurin inhibitor FK506 had no effect. The caspase inhibitors carbobenzoxy-Leu-Glu-His-Asp-CH(2)F and carbobenzoxy-Asp-Glu-Val-Asp-CH(2)F, but not carbobenzoxy-Ile-Glu-Thr-Asp-CH(2)F, differentially blocked post-mitochondrial events. The levels of reduced and oxidized glutathione and pyridine nucleotides in rods were unchanged. Our results demonstrate that rod mitochondria are the target site for Ca(2+) and Pb(2+). Moreover, they suggest that Ca(2+) and Pb(2+) bind to the internal metal (Me(2+)) binding site of the PTP and subsequently open the PTP, which initiates the cytochrome c-caspase cascade of apoptosis in rods.
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PMID:Lead and calcium produce rod photoreceptor cell apoptosis by opening the mitochondrial permeability transition pore. 1076 53

Cells of oligodendroglial lineage are susceptible to oxygen and glucose deprivation. When oligodendrocyte-like cells differentiated from CG-4-immortalized rat O-2A progenitor cells were exposed to hypoxia alone or glucose deprivation alone for 48 h, release of lactate dehydrogenase (LDH) into the culture medium did not increase. However, when cells were deprived of both oxygen and glucose for 6 or 12 h preceding reoxygenation for 2 h, LDH release increased. Adding glucose to the medium protected against cell death and increased lactate production in a concentration-dependent manner. Cell damage induced by deprivation of oxygen and glucose was prevented by calcium-free medium or by non-N-methyl-D-aspartate glutamate receptor (GluR) antagonists, such as 6-cyano-7-nitroquinoxaline-2,3-dione or LY293558, but not by the voltage-dependent calcium channel blocker, nimodipine, or by the N-methyl-D-aspartate GluR antagonist, MK-801. The glutamate concentration in the medium from cells exposed to oxygen-glucose deprivation for 12 h was 49.70+/-3.04 microM/l, which is sufficient to activate GluRs during deprivation of oxygen and glucose. Apoptotic cells detected by terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin nick end-labeling (TUNEL) or Hoechst 33258 staining did not increase in cells exposed to oxygen-glucose deprivation for 12 h and subsequent reoxygenation for 2 h. No DNA laddering was detected by agarose gel electrophoresis from cells exposed to deprivation of oxygen and glucose. Neither acetyl-YVAD-CHO, an inhibitor of caspase-1-like proteases, nor acetyl-DEVD-CHO, an inhibitor of caspase-3-like proteases, prevented oxygen-glucose deprivation-induced injury. Thus, oxygen and glucose deprivation causes calcium-influx-induced necrotic cell damage in cells of oligodendroglial lineage via non-N-methyl-D-aspartate GluR channels.
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PMID:Non-N-methyl-D-aspartate glutamate receptors mediate oxygen--glucose deprivation-induced oligodendroglial injury. 1078 23

To test the apoptotic potential of the nephrotoxic mycotoxin ochratoxin A (OTA), we exposed human proximal tubule-derived cells (IHKE cells) for various times to OTA concentrations close to those occurring during dietary exposure (from 2 to 100 nmol/L) and investigated caspase 3 activation, chromatin condensation, and DNA fragmentation. OTA induced a time- and concentration-dependent activation of caspase 3: concentrations as low as 5 nmol/L OTA caused a slight but significant increase in caspase 3 activity after 7 days of OTA exposure. Exposure to 10 nmol/L OTA for 72 or 24 h led to a significantly increased activity of caspase 3 in human proximal tubule-derived cells. Radical scavengers such as N-acetylcysteine had no effect on OTA-induced caspase 3 activation. Chelation of intracellular calcium with 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid tetrakis (acetoxymethylester) (BAPTA-AM) also showed no effect. Exposure to 30 nmol/L or more OTA led to DNA fragmentation and chromatin condensation in IHKE cells. Cultured renal epithelial MDCK-C7 and MDCK-C11 or OK cells also showed increased caspase 3 activity after OTA exposure. We conclude that exposure to low OTA concentrations can lead to direct or indirect caspase 3 activation and subsequently to apoptosis in cultured human proximal tubule cells and in other renal epithelial cell lines of different origins.
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PMID:The nephrotoxin ochratoxin A induces apoptosis in cultured human proximal tubule cells. 1081 36

The actin regulatory protein gelsolin cleaves actin filaments in a calcium- and polyphosphoinositide-dependent manner. Gelsolin has recently been described as a novel substrate of the cysteinyl protease caspase-3, an effector protease activated during apoptosis. Cleavage by caspase-3 generates an amino-terminal fragment of gelsolin that can sever actin filaments independently of calcium regulation. The disruption of the actin cytoskeleton by cleaved gelsolin is hypothesized to mediate many of the downstream morphological changes associated with apoptosis. In contrast, overexpression of full-length gelsolin has also been reported to inhibit apoptotic cell death upstream of the activation of caspase-3, suggesting that gelsolin may also act prior to commitment to cell death. The authors previously observed that actin stabilization by the cell permeant agent jasplakinolide enhanced cell death upon interleukin (IL)-2 or IL-3 withdrawal from growth-factor-dependent lymphocyte cell lines, and hypothesized that actin polymerization could alter the activity of gelsolin, thus enhancing apoptosis. Here the authors show that constitutive overexpression of gelsolin did not, however, inhibit or dramatically enhance apoptotic cell death upon growth-factor withdrawal, nor did it modify sensitivity to jasplakinolide. In contrast to previous reports, overexpression of gelsolin in Jurkat T cells did not prevent or delay apoptosis induced by Fas ligation or ceramide treatment. Overexpressed gelsolin protein was cleaved during apoptosis, as seen previously in this and other cell types. In these model systems, therefore, the level of gelsolin expression was not a rate-limiting determinant in commitment to or time to the morphological changes of apoptosis.
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PMID:Failure of gelsolin overexpression to regulate lymphocyte apoptosis. 1082 33

The rate of osteoblast apoptosis is a critical determinant of the rate of bone formation. Because the calcium-binding protein calbindin-D(28k) has anti-apoptotic properties in neuronal cells and lymphocytes, we searched for the presence of this protein in osteoblastic cells and investigated whether it can modify their response to proapoptotic signals. Calbindin-D(28K) was expressed at low levels in several osteoblastic cell lines and at high levels in primary cultures of murine osteoblastic cells. Transient transfection of rat calbindin-D(28k) cDNA blocked tumor necrosis factor alpha (TNFalpha)-induced apoptosis in osteoblastic MC3T3-E1 cells, as determined by cell viability and nuclear morphology of cells cotransfected with the green fluorescent protein targeted to the nucleus, whereas transfection of the empty vector had no effect. Calbindin-D(28k) levels in several stably transfected MC3T3-E1 lines were directly related to protection from TNFalpha-induced apoptosis. Purified rat calbindin-D(28k) markedly reduced the activity of caspase-3, a critical molecule for the degradation phase of apoptosis, in a cell-free assay. In addition, cell extracts from MC3T3-E1 cells expressing high levels of calbindin-D(28k) decreased caspase-3 activity, compared with extracts from vector-transfected cells. This effect was apparently unrelated to the calcium binding properties of calbindin, as chelation of calcium by EGTA or addition of other calcium-binding proteins such as calbindin-D(9k), S100, calmodulin, and osteocalcin, did not affect caspase-3 activity. Last, calbindin-D(28k) interacts with the active form of caspase-3 as demonstrated by a GST pull-down assay. These results demonstrate that calbindin-D(28k) is a biosynthetic product of osteoblasts with a role in the regulation of apoptosis. They also reveal that the antiapoptotic properties of calbindin-D(28k) may result not only from calcium buffering but also from the ability of the protein to interact with and to inhibit caspase-3 activity, a property that is independent of its calcium binding capability.
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PMID:Calbindin-D28k is expressed in osteoblastic cells and suppresses their apoptosis by inhibiting caspase-3 activity. 1083 28

Heat shock protein 70 (hsp70) is a stress-inducible protein that prevents apoptosis induced by a wide range of cytotoxic agents by an as yet undefined mechanism. The caspase family of cysteine proteases have been attributed a central role in the execution of apoptosis. However, several cases of caspase-independent apoptosis have been recently reported, suggesting that caspases may not be necessary for apoptosis in all cells. This study examines the protective role of hsp70 in both caspase-dependent and -independent apoptosis. Hydrogen peroxide (H2O2) used at low and high concentrations in Jurkat T cells induces caspase-dependent and -independent apoptosis, respectively. A hsp70-transfected Jurkat clone was used to observe the protection mediated by hsp70 during these two forms of apoptosis. Results reveal that hsp70 inhibits both caspase-dependent and -independent apoptosis. Furthermore, measurement of caspase-3 activity during caspase-dependent apoptosis revealed that caspase activation was inhibited in hsp70 transfectants. Early apoptotic events, such as mitochondrial depolarization, cytochrome c release, and increased intracellular calcium, were demonstrated to be common to both caspase-dependent and -independent H2O2-induced apoptosis. The inhibition of these events by hsp70 suggests that hsp70 may be an important anti-apoptotic regulator, functioning at a very early stage in the apoptotic pathway.
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PMID:Heat shock protein 70 inhibits caspase-dependent and -independent apoptosis in Jurkat T cells. 1085 54

The purpose of the present study was to investigate the mechanisms involved in the induction of apoptosis in newborn cultured cardiomyocytes by activation of adenosine (ADO) A3 receptors and to examine the protective effects of beta-adrenoceptors. The selective agonist for A3 ADO receptors Cl-IB-MECA (2-chloro-N6-iodobenzyl-5-N-methylcarboxamidoadenosine) and the antagonist MRS1523 (5-propyl-2-ethyl-4-propyl-3-(ethylsulfanylcarbonyl)-6-phenylpy rid ine-5-carboxylate) were used. High concentrations of the Cl-IB-MECA (> or = 10 microM) agonist induced morphological modifications of myogenic cells, such as rounding and retraction of cell body and dissolution of contractile filaments, followed by apoptotic death. In addition, Cl-IB-MECA caused a sustained and reversible increase in [Ca2+]i, which was prevented by the selective antagonist MRS1523. Furthermore, MRS1523 protected the cardiocytes if briefly exposed to Cl-IB-MECA and partially protected from prolonged (48 h) agonist exposure. Apoptosis induced by Cl-IB-MECA was not redox-dependent, since the mitochondrial membrane potential remained constant until the terminal stage of cell death. Cl-IB-MECA activated caspase-3 protease in a concentration-dependent manner after 7 h of treatment and more effectively after 18 h of exposure. Bcl-2 protein was readily detected in control cells, and its expression was significantly decreased after 24 and 48 h of treatment with Cl-IB-MECA. Beta-adrenergic stimulation antagonized the pro-apoptotic effects of Cl-IB-MECA, probably through a cAMP/protein kinase A-independent mechanism, since addition of dibutyryl-cAMP did not abolish the apoptosis induced by Cl-IB-MECA. Incubation of cultured myocytes with isoproterenol (5 microM) for 3 or 24 h almost completely abolished the increase in [Ca2+]i. Prolonged incubation of cardiomyocytes with isoproterenol and Cl-IB-MECA did not induce apoptosis. Our data suggest that the apoptosis-inducing signal from activation of adenosine A3 receptors (or counteracting beta-adrenergic signal) leads to the activation of the G-protein-coupled enzymes and downstream pathways to a self-amplifying cascade. Expression of different genes within this cascade is responsible for orchestrating either cardiomyocyte apoptosis or its protection.
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PMID:Induction of apoptosis in rat cardiocytes by A3 adenosine receptor activation and its suppression by isoproterenol. 1085 59


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