Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: 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)

We have attempted to elucidate the precise mechanism of nitric oxide (NO)-induced apoptotic neuronal cell death. Enzymatic cleavages of DEVD-AFC, VDVAD-AFC, and LEHD-AFC (specific substrates for caspase-3-like protease (caspase-3 and -7), caspase-2, and caspase-9, respectively) were observed by treatment with NO. Western blot analysis showed that pro-forms of caspase-2, -3, -6, and -7 are decreased during apoptosis. Interestingly, Ac-DEVD-CHO, a caspase-3-like protease inhibitor, blocked not only the decreases in caspase-2 and -7, but also the formation of p17 from p20 in caspase-3 induced by NO, suggesting that caspase-3 exists upstream of caspase-2 and -7. Bongkrekic acid, a potent inhibitor of mitochondrial permeability transition, specifically blocked both the loss of mitochondrial membrane potential and subsequent DNA fragmentation in response to NO. Thus, NO results in neuronal apoptosis through the sequential loss of mitochondrial membrane potential, caspase activation, and degradation of inhibitor of caspase-activated DNase (CAD) (CAD activation).
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PMID:Mechanism of nitric oxide-induced apoptosis in human neuroblastoma SH-SY5Y cells. 1107 88

Resolving inflammation is a vital step in preventing the persistence of inflammatory disorders. Neutrophils play a major role in tissue damage associated with an inflammatory response. Their death by apoptosis is central to the final resolution of this response. Thiol depletion with diethylmaleate (DEM) or diamide represent important triggers for neutrophil apoptosis. The mechanism by which this process occurs remains unknown. The apoptotic cascade is associated with a number of cellular changes, including caspase activation and mitochondrial permeability. The aims of this study were to determine the role of mitochondrial permeability and the caspase cascade in thiol depletion-induced neutrophil apoptosis. Total cellular glutathione was reduced by DEM and diamide. This reduction was associated with neutrophil apoptosis and an increase in caspase 3 activity. The effects of DEM were blocked by the caspase 3 inhibitor, Z-DEVD-FMK. Mitochondrial permeability that occurred was also increased during this induction of apoptosis. Bongkrekic acid, a mitochondrial membrane stabilizer, inhibited DEM-induced apoptosis. The inhibitors' effects of LPS or GM-CSF on spontaneous neutrophil apoptosis was reversed by DEM, which was mediated by an increase in caspase 3 activity and independent of mitochondrial disruption. Caspase activation is an important step in glutathione depletion-induced apoptosis in resting and inflammatory neutrophils. Regulation of caspase activity may represent a possible target to trigger apoptosis and resolve inflammatory disorders.
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PMID:Glutathione depletion-induced neutrophil apoptosis is caspase 3 dependent. 1113 9

Activation of terminal caspases such as caspase-3 plays an important role in the execution of neuronal cell death after transient cerebral ischemia. Although the precise mechanism by which terminal caspases are activated in ischemic neurons remains elusive, recent studies have postulated that the mitochondrial cell death-signaling pathway may participate in this process. The bcl-2 family member protein Bax is a potent proapoptotic molecule that, on translocation from cytosol to mitochondria, triggers the activation of terminal caspases by increasing mitochondrial membrane permeability and resulting in the release of apoptosis-promoting factors, including cytochrome c. In the present study, the role of intracellular Bax translocation in ischemic brain injury was investigated in a rat model of transient focal ischemia (30 minutes) and reperfusion (1 to 72 hours). Immunochemical studies revealed that transient ischemia induced a rapid translocation of Bax from cytosol to mitochondria in caudate neurons, with a temporal profile and regional distribution coinciding with the mitochondrial release of cytochrome c and caspase-9. Further, in postischemic caudate putamen in vivo and in isolated brain mitochondria in vitro, the authors found enhanced heterodimerization between Bax and the mitochondrial membrane permeabilization-related proteins adenine nucleotide translocator (ANT) and voltage-dependent anion channel. The ANT inhibitor bongkrekic acid prevented Bax and ANT interactions and inhibited Bax-triggered caspase-9 release from isolated brain mitochondria in vitro. Bongkrekic acid also offered significant neuroprotection against ischemia-induced caspase-3 and caspase-9 activation and cell death in the brain. These results strongly suggest that the Bax-mediated mitochondrial apoptotic signaling pathway may play an important role in ischemic neuronal injury.
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PMID:Intracellular Bax translocation after transient cerebral ischemia: implications for a role of the mitochondrial apoptotic signaling pathway in ischemic neuronal death. 1132 18

Mitochondria play a central role in many apoptotic reactions. Although mitochondrial apoptotic changes and caspase activation have been demonstrated in the apoptotic thymocytes, cell death signal through mitochondria in TCR-stimulated thymocytes has not been fully understood. In this study, we show that TCR stimulation induced disruption of mitochondrial transmembrane potential (Delta Psi(m)), the cytochrome c release from mitochondira, capase-3 activation, and the cell death of thymocytes. Bongkrekic acid, an inhibitor of Delta Psi(m) disruption, blocked the cytochrome c release from mitochondria and the following caspase-3-mediated cell death. Furthermore, a pro-apoptotic Bcl-2 family protein, Bax, but not Bad or Bid, was translocated from cytosol to mitochondria in TCR-stimulated thymocytes. This translocation and the following apoptotic changes were inhibited by SB203580, a p38 kinase inhibitor, in a specific manner. These results suggest that activated p38 kinase pathway by TCR stimulation induces translocation of Bax to mitochondria, causing Delta Psi(m) disruption, and the release of cytochrome c, which finally induces caspase-3-mediated apoptosis in thymocytes.
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PMID:Differential involvement of p38 MAP kinase pathway and Bax translocation in the mitochondria-mediated cell death in TCR- and dexamethasone-stimulated thymocytes. 1153 68

Neuronal apoptosis has been implicated as an important mechanism of cell death in acute and chronic neurodegenerative disorders. Ceramide is a product of sphingolipid metabolism which induces neuronal apoptosis in culture, and ceramide levels increase in neurons during various conditions associated with cell death. In this study we investigate the mechanism of ceramide-induced apoptosis in primary cortical neuronal cells. We show that ceramide treatment initiates a cascade of biochemical alterations associated with cell death: earliest signal transduction changes involve Akt dephosphorylation and inactivation followed by dephosphorylation of proapoptotic regulators such as BAD (proapoptotic Bcl-2 family member), Forkhead family transcription factors, glycogen synthase kinase 3-beta, mitochondrial depolarization and permeabilization, release of cytochrome c into the cytosol, and caspase-3 activation. Bongkrekic acid, an agent that inhibits mitochondrial depolarization, significantly reduces ceramide-induced cell death and correlated caspase-3 activation. Together, these data demonstrate the importance of the mitochondrial-dependent intrinsic pathway of caspase activation for ceramide-induced neuronal apoptosis.
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PMID:Ceramide-induced neuronal apoptosis is associated with dephosphorylation of Akt, BAD, FKHR, GSK-3beta, and induction of the mitochondrial-dependent intrinsic caspase pathway. 1269 38

alpha-Hederin, a pentacyclic triterpene saponin isolated from the seeds of Nigella sativa, was recently reported to have potent in vivo antitumor activity against LL/2 (Lewis Lung carcinoma) in BDF1 mice. In this study we observed that alpha-hederin caused a dose- and time-dependent increase in apoptosis of murine leukemia P388 cells. In order to evaluate the possible mechanisms for apoptosis, the effects of alpha-hederin on intracellular thiol concentration, including reduced glutathione (GSH), and protein thiols, and the effects of pretreatment with N-acetlycysteine (NAC), a precursor of intracellular GSH synthesis, or buthionine sulfoxime (BSO), a specific inhibitor of intracellular GSH synthesis, on alpha-hederin-induced apoptosis were investigated. It was found that alpha-hederin rapidly depleted intracellular GSH and protein thiols prior to the occurrence of apoptosis. NAC significantly alleviated alpha-hederin-induced apoptosis, while BSO augmented alpha-hederin-induced apoptosis significantly. The depletion of cellular thiols observed after alpha-hederin treatment caused disruption of mitochondrial membrane potential (deltapsi(m)) and subsequently increased the production of reactive oxygen species (ROS) in P388 cells at an early time point. Bongkrekic acid (BA), a ligand of the mitochondrial adenine nucleotide translocator, and cyclosporin (CsA) attenuated the alpha-hederin-induced loss of deltapsi(m), and ROS production. Thus, oxidative stress after alpha-hederin treatment is an important event in alpha-hederin-induced apoptosis. As observed in this study, permeability transition of mitochondrial membrane occurs after depletion of GSH and precedes a state of reactive oxygen species (ROS) generation. Further, we observed that alpha-hederin caused the release of cytochrome c from the mitochondria to cytosol, leading to caspase-3 activation. Our findings thus demonstrate that changes in intracellular thiols and redox status leading to perturbance of mitochondrial functions are important components in the mechanism of alpha-hederin-induced cell death.
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PMID:Intracellular glutathione depletion and reactive oxygen species generation are important in alpha-hederin-induced apoptosis of P388 cells. 1270 52

Axotomy induces apoptosis in motoneurons of neonatal rodents. To identify the key players in motoneuron apoptosis, we assessed the progression of apoptosis at 4 h intervals following facial motoneuron axotomy. The mitochondrial release of cytochrome c, caspase-3 activation and nuclear condensation were first observed in the motoneuron cell bodies 16 h postaxotomy. In vivo application of inhibitors of the mitochondrial permeability transition pore, Bongkrekic acid and cyclosporin A prevented cytochrome c release as well as caspase-3 activation and attenuated motoneuron apoptosis. Similarly, in vivo application of RU360, an inhibitor of the mitochondrial calcium uniporter, also protected axotomized motoneurons from apoptosis. Taken together, our results show that cytochrome c release and subsequent caspase-3 activation are critical events that precipitate the apoptotic death of axotomized neonatal motoneurons in vivo. In addition, these results provide evidence that application of mitochondrial pore inhibitors in vivo can block the induction of apoptosis following motoneuron axotomy.
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PMID:In vivo application of mitochondrial pore inhibitors blocks the induction of apoptosis in axotomized neonatal facial motoneurons. 1293 71

Neuroblastoma, a pediatric peripheral nervous system tumor, frequently contains alterations in apoptotic pathways, producing chemoresistant disease. Insulin-like growth factor (IGF) system components are highly expressed in neuroblastoma, further protecting these cells from apoptosis. This study investigates IGF-I regulation of apoptosis at the mitochondrial level. Elevated extracellular glucose causes rapid mitochondrial enlargement coupled with an increase in the mitochondrial membrane potential (Delta Psi(M)) followed by mitochondrial membrane depolarization (MMD), uncoupling protein 3 (UCP3) downregulation, caspase-3 activation and decreased Bcl-2. MMD inhibition by Bongkrekic acid prevents high-glucose-induced loss of UCP3 and apoptosis. Glucose exposure induces caspase-9 cleavage within 30 min, and caspase-9 inhibition prevents glucose-mediated apoptosis. IGF-I prevents caspase activation and mitochondrial events leading to apoptosis. These results suggest that elevated glucose produces early initiator caspase activation, followed by Delta Psi(M) changes, in neuroblastoma cells; in turn, IGF-I prevents apoptosis by preventing downstream caspase activation, maintaining Delta Psi(M) and regulating Bcl proteins.
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PMID:Insulin-like growth factor-I regulates glucose-induced mitochondrial depolarization and apoptosis in human neuroblastoma. 1510 34

The soy isoflavone genistein has been identified as having antiproliferative and apoptotic effects on various malignant cell types derived from solid tumors. Because little information regarding the effect of genistein on hematopoietic malignancies is available, we undertook this study of T-cell lymphomas. We tested the effect of genistein on murine T-cell lines derived from thymic lymphomas induced by an oncogenic murine leukemia virus. When T lymphoma cells were treated with genistein concentrations of 15 microM and greater, it was observed that the percentage of viable cells was significantly reduced in a dose- and time-dependent manner. The observed cell killing was found to be the result of apoptosis as detected by flow cytometric analysis of cells stained with annexin V and propidium iodide and assays for caspase-3 activation and DNA fragmentation. Cell staining with the mitochondrial specific dye JC-1 and detection of caspase-9 activation revealed that genistein produced mitochondrial depolarization as an early step in the induction of apoptosis. Bongkrekic acid inhibition of mitochondrial depolarization identified the mitochondria permeability transition pore (PTP) as a potential target of genistein activity. These results indicate that the induction of apoptosis by pharmacological concentrations of genistein in T lymphoma cells occurs via mitochondrial damage with the involvement of the PTP.
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PMID:Genistein induces apoptosis in T lymphoma cells via mitochondrial damage. 1574 35

Photodynamic therapy (PDT) with endogenous protoporphyrin IX derived from 5-aminolevulinic acid or its derivatives has been established for treatments of several premalignancies and malignancies; however, the mechanism of the modality is not fully elucidated. The mitochondrial permeability transition pore consists mainly of the mitochondrial outer membrane voltage-dependent anion channel and the peripheral benzodiazepine receptor (PBR) and the mitochondrial inner membrane adenine nucleotide translocator (ANT). These mitochondrial proteins are responsible for the permeability transition that leads to apoptosis. In the present study, the human leukemia cell line, Reh, was treated with PDT using hexaminolevulinate (HAL). More than 80% of apoptotic Reh cells were found after HAL-mediated PDT (HAL-PDT) with high-molecular-weight (50 kbp) DNA fragmentation. Addition of PK11195 or Ro5-4864, two ligands of PBR, during HAL-PDT significantly inhibited the apoptotic effect. Bongkrekic acid, a ligand for ANT, also reduced the PDT effect. Although the mitochondrial transmembrane potential collapsed, neither cytosolic translocation of mitochondrial cytochrome c nor activation of caspase-9, caspase-8, caspase-3, and poly(ADP-ribose) polymerase were found. However, nuclear translocation of mitochondrial apoptosis-inducing factor (AIF) was shown by both immunoblotting and immunocytochemistry. Because AIF is the sole one among all proapoptotic factors involved in caspase-dependent and caspase-independent pathways that induces the high-molecular-weight DNA fragmentation, we conclude that HAL-PDT specifically targets PBR, leading to apoptosis of the Reh cells through nuclear translocation of mitochondrial AIF. This study suggests PBR as a possible novel therapeutic target for HAL-based PDT of cancer.
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PMID:Targeting PBR by hexaminolevulinate-mediated photodynamic therapy induces apoptosis through translocation of apoptosis-inducing factor in human leukemia cells. 1632 55


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