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)

Epidemiological and experimental carcinogenesis studies provide evidence that components of garlic (Allium sativum) have anticancer activity. We recently reported that the garlic derivative S-allylmercaptocysteine (SAMC) inhibits growth, arrests cells in G(2)-M, and induces apoptosis in human colon cancer cells (Shirin et al., Cancer Res., 61: 725-731, 2001). Because a fraction of the SAMC-treated cells are specifically arrested in mitosis, we examined the mechanism of this effect in the present study. Immunofluorescent microscopy revealed that the treatment of SW480 cells or NIH3T3 fibroblasts with 150 micro M SAMC (the IC(50) concentration) caused rapid microtubule (MT) depolymerization, MT cytoskeleton disruption, centrosome fragmentation and Golgi dispersion in interphase cells. It also induced the formation of monopolar and multipolar spindles in mitotic cells. In vitro turbidity assays indicated that SAMC acted directly on tubulin to cause MT depolymerization, apparently because it interacts with -SH groups on tubulin. To investigate the signaling pathways involved in SAMC-induced apoptosis, we assayed c-Jun NH(2)-terminal kinase (JNK) activity and found that treatment with SAMC caused a rapid and sustained induction of JNK activity. The selective JNK inhibitor SP600125 inhibited the early phase (24 h) but not the late phase (48 h and later) of apoptosis induced by SAMC. Expression of a dominant-negative mutant of JNK1 in SW480 cells inhibited apoptosis induced by SAMC at 24 h but had no protective effect at 48 h. JNK1(-/-) mouse embryonic fibroblasts were resistant to SAMC-induced apoptosis at 24 h but not at 48 h. On the other hand, the inhibition or abrogation of JNK1 activity did not inhibit the G(2)-M arrest induced by SAMC. SAMC also activated caspase-3. The general caspase inhibitor z-VAD-fmk inhibited both early and late phases of apoptosis induced by SAMC. We conclude that the garlic-derived compound SAMC exerts antiproliferative effects by binding directly to tubulin and disrupting the MT assembly, thus arresting cells in mitosis and triggering JNK1 and caspase-3 signaling pathways that lead to apoptosis.
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PMID:Induction of apoptosis by the garlic-derived compound S-allylmercaptocysteine (SAMC) is associated with microtubule depolymerization and c-Jun NH(2)-terminal kinase 1 activation. 1458 80

Sulforaphane (SFN) and its N-acetyl-L-cysteine (NAC) conjugate are effective inhibitors of tumorigenesis in animal models. These compounds induce the expression of the antioxidant response element (ARE)-related genes and cause apoptosis. We studied the role of reduced glutathione (GSH) in the activations of ARE-mediated gene expression, apoptosis, and the activation of c-Jun NH(2)-terminal kinase (JNK) in HepG2-C8 cells. The cellular level of GSH decreased transiently when cells were exposed to SFN and then increased from 4 h, reaching 2.2-fold over control at 24 h. In contrast, SFN-NAC did not change the GSH level substantially during the time of incubation. ARE expression was increased in a dose-dependent manner up to 35 micro M SFN and 75 micro M SFN-NAC, respectively. The induction of ARE by SFN was 8.6-fold higher than that by SFN-NAC. Pretreatment with L-buthionine sulfoximine increased SFN-induced ARE expression significantly. The decrease in ARE expression at higher concentrations of SFN and SFN-NAC was correlated with accelerated apoptotic cell death, with a dose-dependent activation of caspase 3 activity by SFN. On addition of extracellular GSH within 6 h of treatment with SFN, the effect on ARE expression was blocked almost completely. SFN was able to activate JNK1/2, and that activation was blocked by treatment with exogenous GSH. Taken together, these results suggest that the biological effects of SFN and SFN-NAC on the induction of ARE-related gene expression and apoptosis could be different from each other; however, the different effects on ARE-related gene expression and apoptosis elicited by SFN can be blocked by the addition of GSH.
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PMID:Effects of glutathione on antioxidant response element-mediated gene expression and apoptosis elicited by sulforaphane. 1461 54

The c-Jun NH2-terminal kinase (JNK) is involved in the regulation of cell death, but its role in tumor necrosis factor (TNF)-alpha- and Fas-mediated apoptosis in primary cells is not well defined. In primary rat hepatocytes expressing an IkappaB superrepressor, the JNK inhibitor SP600125 strongly decreased TNF-alpha-induced cell death, caspase 3 activation, and DNA laddering. In contrast, SP600125 did not rescue mouse hepatocytes from Fas-induced apoptosis. Apoptosis in mouse hepatocytes, induced by human TNF-alpha, was blocked by SP600125, indicating that TNF-receptor (TNF-R) 1-mediated JNK activation is important for TNF-alpha-induced death. However, mouse TNF-alpha was more efficient than human TNF-alpha in activating JNK and killing mouse hepatocytes, suggesting that TNF-R1 and TNF-R2 cooperate in JNK activation and apoptosis. SP600125 rescued actinomycin D-pretreated hepatocytes and hepatocytes expressing a dominant negative c-Jun from TNF-alpha, indicating that JNK exerts its proapoptotic effect independently of transcription and c-Jun. SP600125 delayed the mitochondrial permeability transition, inhibited cytochrome c release and prevented bid degradation after TNF-alpha, suggesting that JNK-regulated proapoptotic factors act upstream of the mitochondria. Moreover, overexpression of JNK1 activated a mitochondrial death pathway in hepatocytes, albeit less efficiently than TNF-alpha. This study demonstrates that JNK augments TNF-alpha-induced apoptosis in hepatocytes through a signaling pathway that is distinct from the pathway by which it regulates proliferation.
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PMID:Differential requirement for c-Jun NH2-terminal kinase in TNFalpha- and Fas-mediated apoptosis in hepatocytes. 1476 93

Neurotrophins such as nerve growth factor (NGF) are considered putative neuroprotective compounds in the central nervous system. To investigate the cellular and molecular neuroprotective mechanisms of NGF under ischemia, we used a unique oxygen and glucose deprivation (OGD) device. In this system we used pheochromocytoma PC12 cells to elucidate NGF neuroprotective effect. PC12 cells were exposed to OGD, followed by addition of glucose and oxygen (OGD reperfusion). Neuronal cell death induced in this model was measured by the release of lactate dehydrogenase (LDH), activation of caspase-3 and mitogen-activated protein kinases (MAPKs), measured with specific anti-phospho-antibodies. Pretreatment of the cultures with 50 ng/mL NGF, 18 h prior to OGD insult, conferred 30% neuroprotection. However, treatment of the cultures with NGF concomitantly with the OGD insult did not result in neuroprotection. Time-course experiments showed marked activation of extracellular signal-regulated protein kinase, c-Jun N-terminal kinase (JNK), and p38 MAPK isoforms during the OGD phase but not during OGD reperfusion. Pretreatment of the cultures with 50 ng/mL NGF, 18 h prior to OGD insult, resulted in 50% attenuation of OGD-induced activation of JNK1, and 20% and 50% attenuation of OGD-induced activation of p38alpha and beta, respectively. These findings support the notion that NGF confers neuroprotection from OGD insult, a phenomenon coincidentally related to differential inhibition of MAPK stress kinase isoforms, and provide the PC12 model as an in vitro OGD system to investigate molecular mechanisms of neurotoxicity and neuroprotection.
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PMID:Nerve growth factor pretreatment attenuates oxygen and glucose deprivation-induced c-Jun amino-terminal kinase 1 and stress-activated kinases p38alpha and p38beta activation and confers neuroprotection in the pheochromocytoma PC12 Model. 1499 18

We examined the impact of purified bacterially synthesized GST-MDA-7 (IL-24) and ionizing radiation on the proliferation and survival of nonestablished human glioblastoma multiforme (GBM) cells. Glioma cell types expressing mutated PTEN and p53 molecules, activated ERBB1VIII, overexpressing wild type ERBB1 or without receptor overexpression were selected. In MTT assays, GST-MDA-7 caused a dose-dependent reduction in the proliferation of nonestablished glioma cells; however only at higher concentrations did GST-MDA-7 reduce cell viability. The anti-proliferative and cytotoxic effects of GST-MDA-7 were enhanced by radiation in a greater than additive fashion that correlated with JNK1/2/3 activation. The reduction in cell growth and enhancement in cell killing by the combination of GST-MDA-7 and radiation were blocked by an ROS scavenger, N-acetyl cysteine (NAC), a JNK1/2/3 inhibitor SP600125, a pan-caspase inhibitor (zVAD) and by an inhibitor of caspase 9 (LEHD), but not by an inhibitor of caspase 8 (IETD). Low concentrations of either GST-MDA-7 or radiation reduced clonogenic survival, however colony formation ability was significantly further decreased when the two treatments were combined, which was also blocked by inhibition of caspase 9 function. In general agreement with activation of the intrinsic caspase pathway, cell death correlated with reduced BCL-XL expression and with increased levels of the pro-apoptotic proteins BAD and BAX. Inhibition of caspase 9 after combination treatment blunted neither JNK1/2/3 activation nor the enhanced expression of BAD and BAX, but did block caspase 3 cleavage, reduced expression of BCL-XL and inhibition of ERK1/2 activity. In contrast, incubation with NAC blocked JNK1/2/3 activation and cell killing, but not the increases in BAD and BAX expression. These findings argue that after combination treatment JNK1/2/3 activation is a primary pro-apoptotic event and loss of BCL-XL expression and ERK1/2 activity are secondary caspase-dependent processes. This data also argues that GST- MDA-7 induces two parallel pro-apoptotic pathways via ROS-dependent and -independent mechanisms. Infection of primary human astrocytes with a recombinant adenovirus to express MDA-7, Ad.mda-7, but not infection with either Ad.cmv or Ad.mda-7SP- lacking MDA-7 secretion, resulted in the suppression of GBM cell colony formation in soft agar overlay assays, an effect that was enhanced in a greater than additive fashion by radiation. Collectively, our findings demonstrate that MDA-7 reduces proliferation and enhances the radiosensitivity of nonestablished human GBM cells in vitro, and when grown in 3 dimensions, and that sensitization occurs independently of basal EGFR/ERK1/2/AKT activity or the functions of PTEN and p53.
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PMID:MDA-7 regulates cell growth and radiosensitivity in vitro of primary (non-established) human glioma cells. 1532 89

Viscum album L. coloratum agglutinin (VCA), isolated from Korean mistletoe, is a strong inducer of apoptosis in a variety of tumor cells; however, the underlying molecular mechanisms responsible are not clear. Here, we show that VCA induces apoptotic killing, as demonstrated by DNA fragmentation, Hoechst 33258 staining, terminal deoxynucleotidyl transferase dUTP nick-end labeling assay, and flow cytometry analysis in hepatocarcinoma Hep3B cells. VCA treatment results in a significant increase in reactive oxygen species (ROS) and loss of mitochondrial membrane potential (DeltaPsim). Furthermore, treatment with the antioxidant N-acetyl-L-cysteine reduces ROS induction by VCA, preventing apoptosis in Hep3B cells, indicating that oxidative stress is involved in VCA-mediated cell death. Our results also show rapid changes in mitochondrial transition permeability, Bax translocation, cytochrome c release, caspase-3 activity, and poly(ADP-ribose) polymerase degradation in Hep3B cells occurring in VCA-induced apoptosis. There is much evidence that implicates c-Jun NH2-terminal kinase (JNK) activation with apoptosis in a variety of cellular and animal models. In this study, we show that VCA induces JNK phosphorylation, which is abolished with pretreatment with a JNK inhibitor. Moreover, Hep3B cells overexpressing JNK1 or stress-activated protein kinase kinase (SEK1) seem to be more susceptible to cell death from ROS and loss of DeltaPsim induced by VCA, whereas expression of dominant-negative JNK1 or SEK1 in Hep3B cells do not. These data suggest that JNK phosphorylation may be a major regulator involved in VCA-induced apoptosis. Together, these results suggest that VCA induces apoptosis by inducing ROS production and a loss of DeltaPsim, in which JNK phosphorylation plays a critical role in these events.
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PMID:Critical role of reactive oxygen species and mitochondrial membrane potential in Korean mistletoe lectin-induced apoptosis in human hepatocarcinoma cells. 1534 45

The c-Jun N-terminal kinases (JNKs) are important mediators of neurodegeneration and their actions include the activation of genetic programs by phosphorylation of the nuclear transcription factor c-Jun/AP-1, the release of cytochrome c or the pro-inflammatory actions of microglia. Recent data, however, provide evidence for physiological functions of JNKs in particular JNK1, and this involves a role of JNKs in the development of the brain and the (functional and/or structural) integrity of the cytoskeleton. Here we summarize our findings on the cytoskeleton-associated actions of JNKs. Thus, JNKs the relevant MAP kinases for the NGF-induced formation and elongation of PC12 cells, and this process is also supported by JNK2 and JNK3 which are commonly considered as pro-apoptotic signal transducers. Importantly, JNK3 is also mandatory for the intact differentiation of neurons since the functional deletion of JNK3 caused apoptotic features such as activation of caspase 3 in untreated P0 primary hippocampal neurons and following glutamate excitotoxicity. Finally, we can visualize the presence of JNKs at the cytoskeleton, axon and growth cones of primary hippocampal neurons and PC12 cells, and this pattern changes following excitatory stimulation with glutamate. Thus, the functional role of JNKs during development and differentiation substantially differs from their degenerative actions in the adult brain.
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PMID:c-Jun N-terminal kinases (JNKs) and the cytoskeleton--functions beyond neurodegeneration. 1546 86

6-Hydroxydopamine (6-OHDA) causes death of dopaminergic neurons by mitochondrial dysfunction with JNKs as central mediators. Here we provide novel insights into specific actions of JNK isoforms in 6-OHDA-induced death of PC12 cells. Twenty five mum 6-OHDA enhanced total JNK activity in the cytoplasm, nucleus, and at the mitochondria. Inhibition of JNKs by 2 mum SP600125 or transfection with dominant-negative JNK2 (dnJNK2) rescued more than 60% of the otherwise dying PC12 cells after 24 h, whereas transfection with dnJNK1 had no protective effects. In contrast to constitutively present JNK1, JNK2 amounts increased in the nucleus and at the mitochondria after 6-OHDA stimulation. JNK inhibition by SP600125 or transfection of dnJNK2 reduced the pool of active JNKs in the nucleus, the release of cytochrome c, as well as the cleavage of caspase-3 and its substrate poly(ADP-ribose) polymerase-1. Transfection with dnJNK1, however, had no effects on the translocation of JNKs to the mitochondria or the release of cytochrome c. Our data provide novel functional insights into the pathological role of individual JNK isoforms, the signalosome at the mitochondria, and the mode of JNK-induced release of cytochrome c.
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PMID:JNK2 translocates to the mitochondria and mediates cytochrome c release in PC12 cells in response to 6-hydroxydopamine. 1550 37

Cd induces oxidative stress and apoptosis in various cells by activating mitogen-activated protein kinases (MAPKs), but the precise signaling components of the MAPK cascade and their role in neuronal apoptosis are still unclear. Here, we report that Cd treatment of SH-SY5Y cells caused apoptosis through sequential phosphorylation of the apoptosis signal regulating kinase 1, MAPK kinase 4, c-Jun N-terminal kinase (JNK), and c-Jun as determined by overexpression of dominant negative (DN) constructs of these genes or using a specific JNK inhibitor SP600125. Both Cd-induced JNK and c-Jun phosphorylation and apoptosis were inhibited dramatically by N-acetyl-L-cysteine, a free radical scavenger. In addition, caspase inhibitors, zDEVD and zVAD, reduced apoptosis but not JNK and c-Jun phosphorylation induced by Cd, while overexpression of DN JNK1 inhibited caspase-3 activity. Taken together, our data suggested that the JNK/c-Jun signaling cascade plays a crucial role in Cd-induced neuronal cell apoptosis and provides a molecular linkage between oxidative stress and neuronal apoptosis.
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PMID:Identification of ASK1, MKK4, JNK, c-Jun, and caspase-3 as a signaling cascade involved in cadmium-induced neuronal cell apoptosis. 1567 Jul 87

Human glutamylcysteine ligase catalytic subunit (GCLC) is the rate-limiting enzyme for glutathione synthesis. The heavy subunit possesses all the catalytic activities. UV irradiation (UV-C, 30 J/m(2)) induced apoptosis in HEK293 cells, but the morphological changes were inhibited significantly by expression of GCLC. MTS assay and flow cytometry results also indicated that GCLC and JNK1(APF) expression enhanced cellular resistance to UV irradiation. Western blotting showed that irradiation strongly activated the c-Jun NH(2)-terminal kinases (JNKs) and caspase-3 as well as p38 in HEK293 cells. Interestingly, existing data show that GCLC blocks JNK1 phosphorylation but does not affect p38 phosphorylation. Therefore, overexpression of GCLC protected HEK293 cells against UV irradiation-induced cell death by inhibiting the phosphorylation and activation of JNK1, concomitantly with the inhibition of caspase-3 activation and p21(WAF1)-luciferase activity downstream of JNK.
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PMID:Human glutamylcysteine synthetase protects HEK293 cells against UV-induced cell death through inhibition of c-Jun NH2-terminal kinase. 1593 21


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