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)

Caspases are a family of cysteine proteases activated during apoptosis. Modification of caspases by nitric oxide and its relevance during apoptosis is currently a controversial subject. In this study we analyzed the S-nitrosated form of caspase-3 at a molecular level. By using electrospray ionization-mass spectrometry, we detected poly-S-nitrosation of caspase-3 with an average of about 2 molecules of NO bound per enzyme. Although NO treatment completely inhibited enzyme activity, S-nitrosation was not restricted to the active site cysteine. Rather, we detected multiple relative mass increases of 30 +/- 1 Da in both the p12 and p17 subunits of caspase-3, corresponding to single to triple S-nitrosation. The stability of these S-nitrosations differed in physiologically relevant concentrations of 5 mM glutathione. Whereas all S-nitroso bonds in the p12 subunit were cleaved with release of NO and partial formation of protein-mixed disulfides with glutathione, a single S-nitrosation in the p17 subunit remained stable. Since this S-nitrosation was not observed in a mutant form of caspase-3 lacking the active site cysteine, we conclude that NO nitrosates the active site cysteine of caspase-3 and that this modification is notably inert to fast trans-nitrosation with glutathione. Furthermore, we provide evidence that treatment of caspase-3 with NO can lead to mixed disulfide formation with glutathione, demonstrating the oxidative character of NO.
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PMID:Mass spectrometric analysis of nitric oxide-modified caspase-3. 1040 38

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.
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PMID:Bcl-2 and Bcl-X(L) block thapsigargin-induced nitric oxide generation, c-Jun NH(2)-terminal kinase activity, and apoptosis. 1040 55

Senile plaques of Alzheimer's brain are characterized by activated microglia and immunoreactivity for the peptide chromogranin A. We have investigated the mechanisms by which chromogranin A activates microglia, producing modulators of neuronal survival. Primary cultures of rat brain-derived microglia display a reactive phenotype within 24 h of exposure to 10 nM chromogranin A, culminating in microglial death via apoptotic mechanisms mediated by interleukin-1beta converting enzyme. The signalling cascade initiated by chromogranin A triggers nitric oxide production followed by enhanced microglial glutamate release, inhibition of which prevents microglial death. The plasma membrane carrier inhibitor aminoadipate and the type II/III metabotropic glutamate receptor antagonist (RS)-alpha-methyl-4-sulphonophenylglycine are equally protective. A significant amount of the released glutamate occurs from bafilomycin-sensitive stores, suggesting a vesicular mode of release. Inhibition of this component of release affords significant microglial protection. Conditioned medium from activated microglia kills cerebellar granule cells by inducing caspase-3-dependent neuronal apoptosis. Brain-derived neurotrophic factor is partially neuroprotective, as are ionotropic glutamate receptor antagonists, and, when combined with boiling of conditioned medium, full protection is achieved; nitric oxide synthase inhibitors are ineffective.
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PMID:Apoptotic pathways mobilized in microglia and neurones as a consequence of chromogranin A-induced microglial activation. 1042 49

Although nitric oxide (NO) induces neuronal cell death under some conditions, it also can prevent apoptosis resulting from growth factor withdrawal. We investigated the molecular mechanism by which NO protects undifferentiated and differentiated PC12 cells from trophic factor deprivation-induced apoptosis. PC12 cells underwent apoptotic death in association with increased caspase-3-like activity, DNA fragmentation, poly(ADP-ribose) polymerase (PARP) cleavage, and cytochrome c release after 24 hr of serum withdrawal. The apoptosis of PC12 cells was inhibited by the addition of NO-generating donor S-nitroso-N-acetylpenicillamine (SNAP) (5-100 microM) and the specific caspase-3-like protease inhibitor Ac-Asp-Glu-Val-Asp-aldehyde (Ac-DEVD-cho) but not the YVADase (or caspase-1-like protease) inhibitor N-acetyl-Tyr-Val-Ala-Asp-aldehyde (Ac-YVAD-cho). SNAP and Ac-DEVD-cho prevented the increase in DEVDase (caspase-3-like protease) activity. The SNAP-mediated suppression of DEVDase activity was only minimally reversed by the incubation of cell lysate with dithiothreitol, indicating that NO did not S-nitrosylate caspase-3-like proteases in PC12 cells. Western blot analysis showed that NO inhibited the proteolytic activation of caspase-3. The cGMP analog 8-bromo-cGMP (8-Br-cGMP) blocked apoptotic cell death, caspase-3 activity and activation, and cytochrome c release. The soluble guanylyl cyclase inhibitor 1-H-oxodiazol-[1,2,4]-[4,3-a] quinoxaline-1-one (CODQ) significantly attenuated NO-mediated, but not 8-Br-cGMP-dependent, inhibition of apoptotic cell death, PARP cleavage, cytochrome c release, and DEVDase activity. Furthermore, the protein kinase G inhibitor KT5823 reversed both SNAP- and 8-Br-cGMP-mediated anti-apoptotic events. All these apoptotic phenomena were also suppressed by NO production through neuronal NO synthase gene transfer into PC12 cells. Furthermore, similar findings were observed in differentiated PC12 cells stimulated to undergo apoptosis by NO donors and NGF deprivation. These findings indicate that NO protects against PC12 cell death by inhibiting the activation of caspase proteases through cGMP production and activation of protein kinase G.
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PMID:Nitric oxide protects PC12 cells from serum deprivation-induced apoptosis by cGMP-dependent inhibition of caspase signaling. 1043 31

Geranylgeranylacetone (GGA) induces apoptosis in human leukemia HL-60 cells in a dose- and time-dependent manner. This effect was completely prevented by the pan-caspase inhibitor z-Val-Ala-Asp(OMe) fluoromethylketone, thereby implicating the caspase cascade in the process. Prior to DNA fragmentation, GGA treatment markedly activated caspase-3(-like) proteases, which might be responsible for the observed apoptosis. In addition, GGA treatment interfered with the processing and membrane localization of Rap1 and Ras, and these changes may be a result of apoptosis. Moreover, nitric oxide donors significantly accentuated the GGA-induced apoptosis, suggesting that the apoptotic pathway induced by GGA might be regulated by a redox-sensitive mechanism. Taken together, these data suggest that the isoprenoid, GGA, is an effective inducer of apoptotic cell death in HL-60 cells.
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PMID:Geranylgeranylacetone induces apoptosis in HL-60 cells. 1046 78

Peroxynitrite, a product of nitric oxide and superoxide, is one of the most potent oxidants and it has been suggested to be involved in many neurodegenerative disorders. The mechanism of the cytotoxicity by peroxynitrite was examined using 3-morpholinosydonimine (SIN-1) as a peroxynitrite donor and SH-SY5Y cells as a model of dopamine neurons. SIN-1 was found to induce apoptotic cell death with typical nucleosomal DNA fragmentation with activation of caspase 3-like proteases. The signal transduction of apoptosis was studied in concern to mitogen-activated protein kinases (MAPKs). After SIN-1 treatment, phosphorylation of p38 was detected, followed by that of Erk. SB202190, an inhibitor of p38, suppressed Erk phosphorylation to the basal level and partially reduced the activation of caspase 3-like proteases and also the cell death. These results suggest that peroxynitrite may activate p38 MAPK pathway to induce apoptosis in dopamine cells via activation of caspase 3-like proteases.
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PMID:Mitogen-activated protein kinase pathway mediates peroxynitrite-induced apoptosis in human dopaminergic neuroblastoma SH-SY5Y cells. 1049 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.
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PMID:Protection against nitric oxide-induced apoptosis in rat mesangial cells demands mitogen-activated protein kinases and reduced glutathione. 1049 57

Varied intensities of nitrotyrosine immunoreactivity were detected by Western blots after the reaction of proteins or enzymes with peroxynitrite (PN), a strong oxidant derived from nitric oxide. Intense immunoreactivity of cAMP-dependent protein kinase, calmodulin and most histones may depend on greater access to tyrosine residues in the reaction, whereas the absence of immunoreactivity of caspase-3, ubiquitin and S-100 proteins may reflect lack of accessibility. In addition, the changes in UV/visible absorbency were observed after PN-treatment of polynucleotides, polypeptides or proteins. Brief PN-treatment of invertase increased its enzymatic activity. Furthermore, PN-treatment of rabbit IgG decreased its recognition by anti-IgG. The results suggest that PN may chemically modify polypeptides, proteins and polynucleotides and may subsequently alter their biological activity.
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PMID:Modification of proteins and polynucleotides by peroxynitrite. 1053 71

Emerging data indicate that growth factors such as insulin-like growth factor-1 (IGF-1) prevent neuronal death due to nitric oxide (NO) toxicity. On the other hand, growth factors can promote cell survival by acting on phosphatidylinositol 3-kinase (PI3-kinase) and its downstream target, serine-threonine kinase Akt, in various types of cells. Here, we examined the mechanism by which IGF-1 inhibits neuronal apoptosis induced by NO in primary hippocampal neurons. IGF-1 was capable of preventing apoptosis and caspase-3-like activation induced by a NO donor, sodium nitroprusside or 3-morpholin-osydnonimine. Incubation of neurons with a P13-kinase inhibitor, wortmannin or LY294002, blocked the effects of IGF-1 on NO-induced neurotoxicity and caspase-3-like activation. In addition, the P13-kinase inhibitors blocked the effect of IGF-1 on down-regulation in Bcl-2 and upregulation in Bax expression induced by NO. Adenovirus-mediated overexpression of the activated form of Akt significantly inhibited NO-induced cell death, caspase-3-like activation, and changes in Bcl-2 and Bax expression. Moreover, expression of the kinase-defective form of Akt almost completely blocked the effects of IGF-1. These findings suggest that activation of Akt is necessary and sufficient for the effect of IGF-1 and is capable of preventing NO-induced apoptosis by modulating the NO-induced changes in Bcl-2 and Bax expression.
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PMID:Activation of Akt kinase inhibits apoptosis and changes in Bcl-2 and Bax expression induced by nitric oxide in primary hippocampal neurons. 1053 63

In this study, both NIH3T3 and Bcl-2 transfected NIH3T3 cells were examined for their propensity to undergo nitroso compound-induced apoptosis. Bcl-2-expressing NIH3T3 prevented N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)- and S-nitrosoglutathione (GSNO)-induced apoptosis as compared with the control NIH3T3 cells. Flow cytometry revealed that NIH3T3 cells treated with MNNG undergo apoptotic death, which occurred after G2-M arrest in the second cycle of cell proliferation. The mechanism of MNNG-induced NIH3T3 cells apoptosis was observed throughout the activation of caspase-3 protease, PARP degradation and cytochrome c release; it was independent of p53 activation. Glutathione-S-transferanse pi (GST pi) is activated through the transcription activation of antioxidant response element (ARE) during MNNG- and GSNO-induced cell apoptosis. Moreover, overexpression of Bcl-2 in NIH3T3 cells can prevent these features of cell death. Furthermore, both MNNG- and GSNO-induced apoptosis of NIH3T3 cells were accompanied with a decrease in the level of glutathione (GSH); whereas Bcl-2 overexpression led to an increase in total cellular glutathione. MNNG was metabolized rapidly to nitric oxide that reacted with glutathione under the catalysis of GSH transferase in NIH3T3 cell to form GSNO. In short, the production of GSNO in cells was found capable of apoptosis initiation while the overexpression of Bcl-2 can prevent MNNG-mediated cell apoptosis through the elevation of glutathione levels.
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PMID:Suppression of N-methyl-N'-nitro-N-nitrosoguanidine- and S-nitrosoglutathione-induced apoptosis by Bcl-2 through inhibiting glutathione-S-transferase pi in NIH3T3 cells. 1059 28


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