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)

The induction of heat shock proteins (HSP) protects isolated islet cells against the cytotoxicity of inflammatory mediators in vitro. Very little information is available about the effect of HSP overexpression on function of preconditioned islet grafts. The present study investigated the function of heat-exposed pig islets after transplantation into immunocompetent mice in comparison with in vitro resistance against inflammatory mediators. Pig islets were preconditioned at 43 degrees C or sham treated prior to subcapsular transplantation into diabetic C57/Bl6j mice. Nondiabetic mice simultaneously receiving preconditioned and control islets were subjected to bilateral nephrectomy for determination of pig insulin. Resistance against H2O2, NO, human Il-1beta, IFN-gamma, or TNF-alpha was assessed by trypan blue exclusion and insulin determination. Heat-induced protein expression was confirmed by Western blot analysis. Graft preconditioning increased resistance against H2O2, NO, or cytokines (p < 0.05) but decreased survival in nondiabetic mice (p < 0.05) and function in diabetic mice (p < 0.01). Upregulation of caspase-3 activity as well as Bax, Fas, FasL, and DFF expression (p < 0.05) indicated simultaneous induction of apoptosis. The coexpression of HSP and proapoptotic proteins reveals the dual character of the stress response simultaneously starting mechanisms for protection and apoptosis. In vitro assays seem to reflect only insufficiently the situation of islets after transplantation.
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PMID:Hyperthermic preconditioning protects pig islet grafts from early inflammation but enhances rejection in immunocompetent mice. 1476 5

Because Fanconi anemia (FA) cells display hypersensitivity to oxidative stress and reactive oxygen species (ROS) that act as second messengers in cellular signaling, we investigated c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (MAPK) activation in two FA-C lymphocyte cell lines (HSC536/N and PD149L) and one FA-A cell line (HSC99) exposed to interferon (IFN)-gamma or H2O2. IFN-gamma induced accumulation of ROS and activation of JNK and p38 in HSC536/N and PD149L but not in HSC99 cells. Higher concentrations of H2O2 were needed to induce moderate intracellular levels of ROS and phosphorylation of MAPKs in FA-A than in FA-C cells. Pre-incubation with dehydroascorbic acid resulted in reduced intracellular ROS levels and inhibition of MAPK activation induced by the above treatments. To define the functional role of JNK and p38 in IFN-gamma signaling, the effects of pharmacological inhibition of the MAPKs on induction of IFN-gamma and anti-Fas antibody responses were determined. Treatment of HSC536/N cells with p38-specific inhibitors partially inhibited caspase-3 activation while pre-incubation with specific inhibitors of JNK had no effect. Altogether, these results suggest that FA-C cells are hypersensitive to IFN-gamma and are more sensitive to oxidative stress than FA-A cells and that IFN-gamma and anti-Fas antibody mediate signals for apoptosis in FA-C cells via p38 but not JNK pathways.
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PMID:The p38 pathway partially mediates caspase-3 activation induced by reactive oxygen species in Fanconi anemia C cells. 1503 5

Resistance to Fas-mediated apoptosis contributes to tumor evasion from the host immune system and enables tumors to mediate alternative responses such as inflammation and angiogenesis. In this study, we investigated the molecular mechanisms of the resistance to Fas-mediated apoptosis and sensitization to Fas-induced cell death by IFN-gamma in human astrocytoma cells. To address this, we investigated the expression of thirty-three genes related to the Fas signal transduction pathways using RNase protection assay in five different human astrocytoma cells. Patterns of expression of these genes were similar between different cell lines and did not correlate with sensitivity to Fas-mediated cell death. Treatment with IFN-gamma increased the mRNA expression of caspases-1, -4 and -7 in addition to those of Fas and TRAIL in a time- and dose-dependent manner. Studies using specific caspase inhibitors showed that Fas-induced cell death was mediated by caspases-1, -3 and 8 in the Fas-sensitive human astrocytoma cell lines, CRT-J and U87-MG. We further demonstrated that these caspases were proteolytically cleaved upon Fas ligation in these cells. Interestingly, caspase-1 protein expression but not that of caspase-3 nor -8 was up-regulated by IFN-gamma only in Fas-sensitive CRT-J cells but not in Fas-resistant U373-MG cells. These results collectively suggest that caspase-1, along with caspases-3 and -8, mediate Fas-induced cell death in human astrocytoma cells, and post-transcriptional regulation of caspase-1 may determine the responsiveness to IFN-gamma-induced sensitization to Fas-mediated apoptosis.
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PMID:Caspase-1 mediates Fas-induced apoptosis and is up-regulated by interferon-gamma in human astrocytoma cells. 1507 64

Although several observations show local T cell recognition of retinal Ag, there has been no direct demonstration that the APC were retinal derived, rather than recruited. In this study, CD45(+) cells isolated from immunologically quiescent murine retina were tested in vitro for functional evidence of Ag presentation to naive and Ag-experienced CD4 T cells specific for beta-galactosidase. Because CD45(+) cells from brain have been reported to be efficient APC, they were included for comparison. Measures of activation included changes in CD4, CD25, CD44, CD45RB, CD62L, CD69, caspase-3 activation, CFSE dilution, size, number of cells recovered, and cytokine production. Retinal CD45(+) cells gave no evidence of Ag-dependent TCR ligation in naive T cells, unlike splenic APC and CD45(+) cells from brain, which supported potent responses. Instead, addition of retinal CD45(+) cells to cocultures of naive 3E9 T cells plus splenic APC reduced the yield of activated T cells and cytokine production by limiting T cell activation at early time points. Ag-experienced T cells responded weakly to Ag presented by retinal CD45(+) cells. Activating the retinal cells with IFN-gamma, anti-CD40, or LPS incrementally increased their APC activity. Addition of neutralizing Abs to TGF-beta did not reveal suppressed retinal APC activity. Because retina lacks tissue equivalents of meninges and choroid plexus, rich sources of dendritic cells in brain, cells from retina may better represent the APC activity of fresh, adult CNS parenchymal and perivascular cells. The activity of the retinal CD45(+) cells appears to be directed to limiting T cell responses.
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PMID:The antigen-presenting activity of fresh, adult parenchymal microglia and perivascular cells from retina. 1515 73

We studied the intracellular events associated with pancreatic beta cell apoptosis by IFN-gamma/TNF-alpha synergism. IFN-gamma/TNF-alpha treatment of MIN6N8 insulinoma cells increased the amplitude of high voltage-activated Ca(2+) currents, while treatment with IFN-gamma or TNF-alpha alone did not. Cytosolic Ca(2+) concentration ([Ca(2+)](c)) was also increased by IFN-gamma/TNF-alpha treatment. Blockade of L-type Ca(2+) channel by nifedipine abrogated death of insulinoma cells by IFN-gamma/TNF-alpha. Diazoxide that attenuates voltage-activated Ca(2+) currents inhibited MIN6N8 cell death by IFN-gamma/TNF-alpha, while glibenclamide that accentuates voltage-activated Ca(2+) currents augmented insulinoma cell death. A protein kinase C inhibitor attenuated MIN6N8 cell death and the increase in [Ca(2+)](c) by IFN-gamma/TNF-alpha. Following the increase in [Ca(2+)](c), calpain was activated, and calpain inhibitors decreased insulinoma cell death by IFN-gamma/TNF-alpha. As a downstream of calpain, calcineurin was activated and the inhibition of calcineurin activation by FK506 diminished insulinoma cell death by IFN-gamma/TNF-alpha. BAD phosphorylation was decreased by IFN-gamma/TNF-alpha because of the increased calcineurin activity, which was reversed by FK506. IFN-gamma/TNF-alpha induced cytochrome c translocation from mitochondria to cytoplasm and activation of caspase-9. Effector caspases such as caspase-3 or -7 were also activated by IFN-gamma/TNF-alpha treatment. These results indicate that IFN-gamma/TNF-alpha synergism induces pancreatic beta cell apoptosis by Ca(2+) channel activation followed by downstream intracellular events such as mitochondrial events and caspase activation and also suggest the therapeutic potential of Ca(2+) modulation in type 1 diabetes.
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PMID:Role of calcium in pancreatic islet cell death by IFN-gamma/TNF-alpha. 1515 22

Brown Norway (BN) and BN Katholiek (BN/Ka) rat strains are both susceptible to develop lesions in the internal elastic lamina (IEL) of the aorta. BN/Ka rats are characterized by a single point mutation in the kininogen gene leading to deficiency in high- and low-molecular-weight kininogen. Recently, a suggestive quantitative trait locus for lesions in the IEL of the abdominal aorta was identified in an F2 intercross between Dahl salt-sensitive (SS) and BN rats, implicating kininogen as a positional candidate gene. Therefore, BN and BN/Ka rat strains represent ideal model organisms with which to study the contribution of kininogen to the genetic predisposition to IEL lesion formation and to characterize the early events underlying vascular remodeling. Here we present data demonstrating that genetic kininogen deficiency promotes the formation of aneurysms in the abdominal aorta but not the development of atherosclerosis upon 12-wk treatment with an atherogenic diet. Aneurysm formation was associated with an enhanced elastolysis, increased expression of MMP-2 and MMP-3, downregulation of TIMP-4, and with FasL- and caspase-3-mediated apoptosis. Kininogen-deficient animals also featured changes in plasma cytokines compatible with apoptotic vascular damage, i.e., upregulation of IFN-gamma and downregulation of GM-CSF and IL-1beta. Finally, in response to atherogenic diet, kininogen-deficient animals developed an increase in HDL/total cholesterol index, pronounced fatty liver and heart degeneration, and lipid depositions in aortic media without atherosclerotic plaque formation. These findings suggest that genetic kininogen deficiency renders vascular tissue prone to aneurysmatic but not to atherosclerotic lesions.
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PMID:Genetic kininogen deficiency contributes to aortic aneurysm formation but not to atherosclerosis. 1523 17

Eosinophils release a number of mediators that are potentially toxic to nerve cells. However, in a number of inflammatory conditions, such as asthma and inflammatory bowel disease, it has been shown that eosinophils localize to nerves, and this is associated with enhanced nerve activity. In in vitro studies, we have shown that eosinophil adhesion via neuronal ICAM-1 leads to activation of neuronal NF-kappaB via an ERK1/2-dependent pathway. In this study, we tested the hypothesis that eosinophil adhesion to nerves promotes neural survival by protection from inflammation-associated apoptosis. Exposure of differentiated IMR-32 cholinergic nerve cells to IL-1beta, TNF-alpha, and IFN-gamma, or culture in serum-deprived medium, induced neuronal apoptosis, as detected by annexin V staining, caspase-3 activation, and DNA laddering. Addition of human eosinophils to IMR-32 nerve cells completely prevented all these features of apoptosis. The mechanism of protection by eosinophils was by an adhesion-dependent activation of ERK1/2, which led to the induced expression of the antiapoptotic gene bfl-1. Adhesion to nerve cells did not influence the expression of the related genes bax and bad. Thus, prevention of apoptosis by eosinophils may be a mechanism by which these cells regulate neural plasticity in the peripheral nervous system.
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PMID:Eosinophil adhesion to cholinergic IMR-32 cells protects against induced neuronal apoptosis. 1552 30

The anthracyclines, such as doxorubicin, are widely used in the treatment of breast cancer. Previously, we showed that these drugs could activate the transcription factor, nuclear factor kappaB, in a DNA damage-dependent manner. We now show that these drugs can potentiate the activation of signal transducer and activator of transcription 1 (STAT1) in MDA-MB 435 breast cancer cells treated with IFN-gamma. We observed that key markers of STAT1 activation, including tyrosine 701 and serine 727 phosphorylation, were enhanced in the presence of doxorubicin. This potentiation resulted in enhanced nuclear localization of activated STAT1 and led to an increase in the nuclear binding of activated STAT complexes. The observed potentiation was specific for STAT1 and IFN-gamma, as no effects were observed with either STAT3 or STAT5. Furthermore, the type I IFNs (alpha and beta) had little or no effect. The observed effects on STAT1 phosphorylation have previously been linked with maximal transcriptional activation and apoptosis. Cell viability was assessed by crystal violet staining followed by analysis with CalcuSyn to determine combination index values, a measure of synergy. We confirmed that significant synergy existed between IFN-gamma and doxorubicin (combination index = 0.34) at doses lower than IC(50) values for this drug (0.67 micromol/L). In support of this, we observed that apoptotic cell death was also enhanced by measuring poly(ADP-ribose) polymerase and caspase-3 cleavage. Finally, suppression of STAT1 expression by small-interfering RNA resulted in a loss of synergistic apoptotic cell death compared with cells, where no suppression of STAT1 expression was attained with scrambled small-interfering RNA control. We conclude that doxorubicin potentiates STAT1 activation in response to IFN-gamma, and that this combination results in enhanced apoptosis in breast cancer cells.
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PMID:STAT1: a modulator of chemotherapy-induced apoptosis. 1554 5

In type 1 diabetes, autoimmune inflammation of pancreatic islets of Langerhans ('insulitis') results in destruction of insulin-producing beta cells. Cytokines released from islet-infiltrating mononuclear cells are known to be cytotoxic both directly and by upregulating Fas for FasL-induced apoptosis. To investigate the role of caspase-3, a major effector of apoptosis in beta-cell death, we asked whether cytokine- and/or FasL-induced apoptosis was associated with increased activity of caspase-3 in NIT-1 insulinoma cells and islets of autoimmune diabetes-prone NOD mice. Measurement of caspase-3 activity using a fluorogenic cleavage assay was validated in NOD mouse thymocytes undergoing dexamethasone (Dex)-induced apoptosis. For cytokine-induced apoptosis, NIT-1 cells or islets were exposed to IL-1 beta and IFN-gamma for 24 h. Caspase-3-like activity was increased 2.1+/-0.7 and 2.4+/-0.9-fold in lysates of cytokine-treated NIT-1 cells and NOD mouse islets, respectively. However, NIT-1 cells exhibited 2.1% (4.7 pg active caspase-3/microg protein) and islets 0.8% (1.9 pg active caspase-3/microg protein) of the active caspase-3 content observed in Dex-treated thymocytes (225.1 pg active caspase-3/microg protein). After 24 h cytokine-exposure, the percentage of Fas-positive NIT-1 cells increased from 1.4+/-1.1 to 29.7+/-11.6%. Addition of FasL for a further 3 h increased caspase-3-like activity an additional 1.8-fold in cytokine-treated NIT-1 cells. In summary, exposure of NOD mouse insulinoma cells or islets to IL-1 beta and IFN-gamma for 24 h induced caspase-3-like activity that, in the case of insulinoma cells at least, can be further enhanced by interaction of cytokine-induced Fas receptor with FasL. Compared to thymocytes, insulinoma cells and islets from NOD mice were characterised by low basal and cytokine-induced caspase-3 activity.
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PMID:Cytokines activate caspase-3 in insulinoma cells of diabetes-prone NOD mice directly and via upregulation of Fas. 1557 24

It has been suggested that antitumor T cells specifically traffic to the tumor site, where they effect tumor destruction. To test whether tumor-reactive CD8(+) T cells specifically home to tumor, we assessed the trafficking of gp100-specific pmel-1 cells to large, vascularized tumors that express or do not express the target Ag. Activation of tumor-specific CD8(+) pmel-1 T cells with IL-2 and vaccination with an altered peptide ligand caused regression of gp100-positive tumors (B16), but not gp100-negative tumors (methylcholanthrene 205), implanted on opposing flanks of the same mouse. Surprisingly, we found approximately equal and very large numbers of pmel-1 T cells (>25% of all lymphocytes) infiltrating both Ag-positive and Ag-negative tumors. We also found evidence of massive infiltration and proliferation of activated antitumor pmel-1 cells in a variety of peripheral tissues, including lymph nodes, liver, spleen, and lungs, but not peripheral blood. Most importantly, evidence for T cell function, as measured by production of IFN-gamma, release of perforin, and activation of caspase-3 in target cells, was confined to Ag-expressing tumor. We thus conclude that CD8(+) T cell-mediated destruction of tumor is the result of specific T cell triggering at the tumor site. The ability to induce ubiquitous homing and specific tumor destruction may be important in the case of noninflammatory metastatic tumor foci.
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PMID:Vaccine-stimulated, adoptively transferred CD8+ T cells traffic indiscriminately and ubiquitously while mediating specific tumor destruction. 1558 42


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