Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have focused on the roles of PARP and poly(ADP-ribosyl)ation early in apoptosis, as well as during the early stages of differentiation-linked DNA replication. In both nuclear processes, a transient burst of PAR synthesis and PARP expression occurs early, prior to internucleosomal DNA cleavage before commitment to apoptosis as well as at the round of DNA replication prior to the onset of terminal differentiation. In intact human osteosarcoma cells undergoing spontaneous apoptosis, both PARP and PAR decreased after this early peak, concomitant with the inactivation and cleavage of PARP by caspase-3 and the onset of substantial DNA and nuclear fragmentation. Whereas 3T3-L1, osteosarcoma cells, and immortalized PARP +/+ fibroblasts exhibited this early burst of PAR synthesis during Fas-mediated apoptosis, neither PARP-depleted 3T3-L1 PARP-antisense cells nor PARP -/- fibroblasts showed this response. Consequently, whereas control cells progressed into apoptosis, as indicated by induction of caspase-3-like PARP-cleavage activity, PARP-antisense cells and PARP -/- fibroblasts did not, indicating a requirement for PARP and poly(ADP-ribosyl)ation of nuclear proteins at an early reversible stage of apoptosis. In parallel experiments, a transient increase in PARP expression and activity were also noted in 3T3-L1 preadipocytes 24 h after induction of differentiation, a stage at which approximately 95% of the cells were in S-phase, but not in PARP-depleted antisense cells, which were consequently unable to complete the round of DNA replication required for differentiation. PARP, a component of the multiprotein DNA replication complex (MRC) that catalyzes viral DNA replication in vitro, poly(ADP-ribosyl)ates 15 of approximately 40 MRC proteins, including DNA pol alpha, DNA topo I, and PCNA. Depletion of endogenous PARP by antisense RNA expression in 3T3-L1 cells results in MRCs devoid of any DNA pol alpha and DNA pol delta activities. Surprisingly, there was no new expression of PCNA and DNA pol alpha, as well as the transcription factor E2F-1 in PARP-antisense cells during entry into S-phase, suggesting that PARP may play a role in the expression of these proteins, perhaps by interacting with a site in the promoters for these genes.
Mol Cell Biochem 1999 Mar
PMID:Involvement of PARP and poly(ADP-ribosyl)ation in the early stages of apoptosis and DNA replication. 1033 50

In this study, we examined the levels of activated caspase-3 in the kainic acid (KA) model of hippocampal degeneration in both sensitive (FVB/N) and resistant (129/SvEMS) strains of mice. At 30 h, 2 and 4 days following KA administration, animals were sacrificed and brains examined for pyknosis, TUNEL labeling, and activated caspase-3 immunoreactivity. Catalytically active caspase-3 was first detected 30 h following KA treatment in the sensitive, FVB/N strain. This was 18 h before the appearance of pyknosis or TUNEL labeling. The expression of activated caspase-3 continues up to 4 days post-injection. No activated caspase-3 immunoreactivity was detected in the resistant, 129/SvEMS strain, neither was there evidence of pyknosis or TUNEL staining. This suggests that activation of caspase-3 is a necessary component of KA-induced cell death.
Brain Res Mol Brain Res 1999 Jun 18
PMID:Caspase-3-dependent neuronal death in the hippocampus following kainic acid treatment. 1038 55

Recently, advances have been made in understanding the molecular mechanisms by which bisphosphonate drugs inhibit bone resorption. Studies with the macrophage-like cell line J774 have suggested that alendronate, an amino-containing bisphosphonate, causes apoptosis by preventing post-translational modification of GTP-binding proteins with isoprenoid lipids. However, clodronate, a nonaminobisphosphonate, does not inhibit protein isoprenylation but can be metabolized intracellularly to a cytotoxic, beta-gamma-methylene (AppCp-type) analog of ATP. These observations raise the possibility that bisphosphonates can be divided into two groups with distinct molecular mechanisms of action depending on the nature of the R2 side chain. We addressed this question by directly comparing the ability of three aminobisphosphonates (alendronate, ibandronate, and pamidronate) and three nonaminobisphosphonates (clodronate, etidronate, and tiludronate) to inhibit protein isoprenylation and activate caspase-3-like proteases or to be metabolized to AppCp-type nucleotides by J774 cells. All three aminobisphosphonates inhibited protein isoprenylation and activated caspase-3-like proteases. Apoptosis and caspase activation after 24-h treatment with the aminobisphosphonates could be prevented by addition of farnesol or geranylgeraniol, confirming that these bisphosphonates inhibit the metabolic mevalonate pathway. No AppCp-type metabolites of the aminobisphosphonates could be detected by mass spectrometry. The three nonaminobisphosphonates did not inhibit protein isoprenylation or cause activation of caspase-3-like proteases, but were incorporated into AppCp-type nucleotides. Taken together, these observations clearly demonstrate that bisphosphonate drugs can be divided into two pharmacological classes: the aminobisphosphonates, which act by inhibiting protein isoprenylation, and the less potent nonaminobisphosphonates, which act through the intracellular accumulation of AppCp-type metabolites.
Mol Pharmacol 1999 Jul
PMID:Farnesol and geranylgeraniol prevent activation of caspases by aminobisphosphonates: biochemical evidence for two distinct pharmacological classes of bisphosphonate drugs. 1038 93

The proteins Bcl-2 and Bcl-X(L) prevent apoptosis, but their mechanism of action is unclear. We examined the role of Bcl-2 and Bcl-X(L) in the regulation of cytosolic Ca(2+), nitric oxide production (NO), c-Jun NH(2)-terminal kinase (JNK) activation, and apoptosis in Jurkat T cells. Thapsigargin (TG), an inhibitor of the endoplasmic reticulum-associated Ca(2+) ATPase, was used to disrupt Ca(2+) homeostasis. TG acutely elevated intracellular free Ca(2+) and mitochondrial Ca(2+) levels and induced NO production and apoptosis in Jurkat cells transfected with vector (JT/Neo). Buffering of this Ca(2+) response with 1, 2-bis(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid tetra(acetoxymethyl) ester (BAPTA-AM) or inhibiting NO synthase activity with N(G)-nitro-L-arginine methyl ester hydrochloride (L-NAME) blocked TG-induced NO production and apoptosis in JT/Neo cells. By contrast, while TG produced comparable early changes in the Ca(2+) level (i.e., within 3 h) in Jurkat cells overexpressing Bcl-2 and Bcl-X(L) (JT/Bcl-2 or JT/Bcl-X(L)), NO production, late (36-h) Ca(2+) accumulation, and apoptosis were dramatically reduced compared to those in JT/Neo cells. Exposure of JT/Bcl-2 and JT/Bcl-X(L) cells to the NO donor, S-nitroso-N-acetylpenacillamine (SNAP) resulted in apoptosis comparable to that seen in JT/Neo cells. TG also activated the JNK pathway, which was blocked by L-NAME. Transient expression of a dominant negative mutant SEK1 (Lys-->Arg), an upstream kinase of JNK, prevented both TG-induced JNK activation and apoptosis. A dominant negative c-Jun mutant also reduced TG-induced apoptosis. Overexpression of Bcl-2 or Bcl-X(L) inhibited TG-induced loss in mitochondrial membrane potential, release of cytochrome c, and activation of caspase-3 and JNK. Inhibition of caspase-3 activation blocked TG-induced JNK activation, suggesting that JNK activation occurred downstream of caspase-3. Thus, TG-induced Ca(2+) release leads to NO generation followed by mitochondrial changes including cytochrome c release and caspase-3 activation. Caspase-3 activation leads to activation of the JNK pathway and apoptosis. In summary, Ca(2+)-dependent activation of NO production mediates apoptosis after TG exposure in JT/Neo cells. JT/Bcl-2 and JT/Bcl-X(L) cells are susceptible to NO-mediated apoptosis, but Bcl-2 and Bcl-X(L) protect the cells against TG-induced apoptosis by negatively regulating Ca(2+)-sensitive NO synthase activity or expression.
Mol Cell Biol 1999 Aug
PMID:Bcl-2 and Bcl-X(L) block thapsigargin-induced nitric oxide generation, c-Jun NH(2)-terminal kinase activity, and apoptosis. 1040 55

The retinoblastoma tumor suppressor protein (RB) has been shown to play a role in regulating the eukaryotic cell cycle, promoting cellular differentiation, and modulating programmed cell death. Although regulation of RB tumor suppressor activity is mediated by reversible phosphorylation, an additional posttranslational modification involves the cleavage of 42 residues from the carboxy terminus of RB during the onset of drug-induced or receptor-mediated apoptosis. We now demonstrate that a recombinant p100cl RB species localizes to the nucleus where it may retain wildtype "pocket" protein binding activity. In addition, using immunocytochemistry, we show that cleavage of the endogenous RB protein occurs in vivo in human cells and that p100cl is predominantly retained within the nuclear compartment of cells during early apoptosis. We also show that the carboxy-terminal cleavage of RB is detected immediately following caspase-3 and PARP cleavage during FAS-mediated apoptosis of MCF10 cells. These findings suggest that this cleavage event may be a component of a downstream cascade during programmed cell death.
Mol Cell Biol Res Commun 1999 Jun
PMID:The 100-kDa proteolytic fragment of RB is retained predominantly within the nuclear compartment of apoptotic cells. 1042 29

We have investigated the possibility of the involvement of PARP in apoptosis, independently of its enzymatic activity. We thus transfected PARP(-)/(-)A11 cells with a DNA construct encoding the PARP DNA-binding domain (DBD) fragment or mutants DBDbd(-), defective in DNA binding to DNA strand breaks, and DBDcl(-), resistant to caspase-3 cleavage. We found that in the absence of PARP, while expression of DBD has only a marginal effect, expression of the mutants strongly inhibits the apoptosis induced by staurosporine, as measured by the binding of annexin V. Moreover, the mutants, but not DBD, inhibit the cleavage of DNA PKcs, suggesting inhibition of activation of caspase-3. In addition, the mutant transfectants are fractionally less susceptible to low doses of an alkylating agent than the DBD transfectant or the original A11 line. The results suggest that the DBD fragment of PARP, apart from its classical role of nick detection and DNA binding, participates in complexes involved in upstream events leading to activation of the caspase cascade.
J Mol Biol 1999 Jul 30
PMID:Inhibition of apoptosis of a PARP(-)/(-)cell line transfected with PARP DNA-binding domain mutants. 1043 94

Some widely used antidepressants such as imipramine, clomipramine, and citalopram have been found to possess antineoplastic effects. In the present study, these compounds were found to induce apoptotic cell death in human acute myeloid leukemia HL-60 cells. Apoptosis induced by the antidepressants was identified by electron microscopy and conventional agarose gel electrophoresis and was quantitated by propodium iodide staining and the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) via flow cytometry. Treatment with apoptosis-inducing concentrations of the antidepressants (80 microM imipramine, 35 microM clomipramine, or 220 microM citalopram) caused induction of caspase-3/caspase-3-like activity, which was monitored by the cleavage of poly(ADP-ribose) polymerase (PARP), the loss of the 32 kD caspase-3 (CPP32) precursor, and the cleavage of the fluorescent CPP32-like substrate PhiPhiLux. Pretreatment with a potent caspase inhibitor benzyloxycarbonyl-Val-Ala-Asp-fluoromethyl-ketone (zVAD-fmk) inhibited antidepressant-induced CPP32/CPP32-like activity and apoptosis. Furthermore, activation of caspase induced by the antidepressants was preceded by the hypergeneration of intracellular reactive oxygen species (ROS). These results suggested that the antidepressants may induce apoptosis via a caspase-3-dependent pathway, and induction of apoptosis by the antidepressants may provide a clue for the mechanism of their antineoplastic effects.
J Biochem Mol Toxicol 1999
PMID:The antidepressants imipramine, clomipramine, and citalopram induce apoptosis in human acute myeloid leukemia HL-60 cells via caspase-3 activation. 1048 22

Inflammatory diseases such as proliferative glomerulonephritis are associated with the production of nitric oxide (NO), which can initiate apoptotic/necrotic cell death. We studied the role of the p42/44 mitogen-activated protein kinases (MAPKs) and c-Jun N-terminal kinases1/2 (JNK1/2) in NO-evoked cytotoxicity in rat mesangial cells (MC). The NO donor S-nitrosoglutathione time- and concentration-dependently promoted apoptotic cell death as detected by JNK1/2 and caspase-3 activation as well as DNA fragmentation. By using Ro 318220, a JNK1/2 activator, we established a correlation between apoptosis and JNK1/2 activation. Apoptosis is antagonized by the addition of fetal calf serum or the simultaneous generation of NO and superoxide (O(2)(-)), another biological inflammatory mediator. Fetal calf serum-induced protection required p42/44 MAPK activation as inhibition of the p42/44 MAPK pathway by the MAPK kinase-1 inhibitor PD 98059 attenuated MC protection. In contrast, cytoprotection by NO/O(2)(-) cogeneration demanded reduced glutathione but was p42/44 MAPK unrelated. Depletion of glutathione reversed NO/O(2)(-)-evoked survival to cell destruction and reinstalled JNK1/2 activity. In conclusion, different signal transduction pathways facilitate protection against NO-induced JNK1/2 activation and apoptosis in rat MC.
Mol Pharmacol 1999 Oct
PMID:Protection against nitric oxide-induced apoptosis in rat mesangial cells demands mitogen-activated protein kinases and reduced glutathione. 1049 57

Peroxynitrite is a cytotoxic oxidant produced during shock, ischemia reperfusion, and inflammation. The cellular events mediating the cytotoxic effect of peroxynitrite include activation of poly(ADP-ribose) synthetase, inhibition of mitochondrial respiration, and activation of caspase-3. The aim of the present study was to investigate the role of intracellular calcium mobilization in the necrotic and apoptotic cell death induced by peroxynitrite. Peroxynitrite, in a low, pathophysiologically relevant concentration (20 microM), induces rapid (1 to 3 min) Ca(2+) mobilization in thymocytes. Inhibition of this early calcium signaling by cell-permeable Ca(2+) chelators [EGTA-acetoxymethyl ester (AM), 1, 2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid-AM (BAPTA-AM), 8-amino-2-[(2-amino-5-methylphenoxy)methyl]-6-methoxyquinoline-N,N , N',N'-tetraacetic acid-tetra-AM] abolished cytotoxicity as measured by propidium iodide uptake. Intracellular Ca(2+) chelators also inhibited DNA single-strand breakage and activation of poly(ADP-ribose) synthase (PARS), which is a major mediator of cell necrosis in the current model. Intracellular Ca(2+) chelators also protected PARS-deficient thymocytes from peroxynitrite cytotoxicity, providing evidence for a PARS-independent, Ca(2+)-dependent cytotoxic pathway. Chelation of intracellular Ca(2+) blocked the peroxynitrite-induced decrease of mitochondrial membrane potential, secondary superoxide production, and mitochondrial membrane damage. Peroxynitrite-induced internucleosomal DNA cleavage was increased on BAPTA-AM pretreatment in the wild-type cells but decreased in the PARS-deficient cells. Two other apoptotic parameters (phosphatidylserine exposure and caspase 3 activation) were inhibited by BAPTA-AM in both the wild-type and the PARS-deficient thymocytes. Our findings provide evidence for the pivotal role of an early Ca(2+) signaling in peroxynitrite cytotoxicity.
Mol Pharmacol 1999 Oct
PMID:Requirement of intracellular calcium mobilization for peroxynitrite-induced poly(ADP-ribose) synthetase activation and cytotoxicity. 1049 67

By using flow-cytometric analysis, we examined the involvement of p53, c-Myc, Bcl-2 and Bax in the glutamate-induced cell death in cultured cortical neurons. The activities of caspase-1-like and caspase-3-like proteases were also measured after the glutamate treatment. The apoptosis rate of the cells increased after 12 h and 24 h treatment with glutamate. The temporal profile of p53, c-Myc, Bcl-2, Bax expression and caspases activation after glutamate treatment suggest that Bcl-2, c-Myc and caspase-3 play important roles in the excitotoxic neuronal cell death. The down-regulation of Bcl-2 may be an important early stage event, which may cause the activation of caspase-3. c-Myc is also involved in the process of apoptosis though its precise role remains elusive. bFGF exhibited the capability to antagonize the neuronal apoptosis caused by glutamate. The antiapoptotic potential of bFGF may result from its attenuating effect on the down-regulation of Bcl-2 induced by glutamate and, subsequently, blockade of apoptosis cascade. This may provide a possible explanation for its neuroprotective effect against ischemic cell death.
Brain Res Mol Brain Res 1999 Aug 25
PMID:Roles of p53, c-Myc, Bcl-2, Bax and caspases in glutamate-induced neuronal apoptosis and the possible neuroprotective mechanism of basic fibroblast growth factor. 1052 75


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