Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P05412 (c-Jun)
 11,453 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A novel polyunsaturated fatty acid (PUFA), beta-oxa 21:3n-3, containing an oxygen atom in the beta position, was chemically synthesized, and found to have more selective biological activity than the n-3 PUFA, docosahexaenoic acid (22:6n-3) on cells of the immune system. Although beta-oxa 21:3n-3 was very poor compared with 22:6n-3 at stimulating oxygen radical production in neutrophils, it was more effective at inhibiting human T lymphocyte proliferation (IC(50) of 1.9 vs 5.2 microM, respectively). beta-Oxa 21:3n-3 also inhibited the production of TNF-beta, IFN-gamma, and IL-2 by purified human T lymphocytes stimulated with PHA plus PMA, anti-CD3 plus anti-CD28 mAbs, or PMA plus A23187. Metabolism of beta-oxa 21:3n-3 via the cyclooxygenase and lipoxygenase pathways was not required for its inhibitory effects. Consistent with its ability to suppress T lymphocyte function, beta-oxa 21:3n-3 significantly inhibited the delayed-type hypersensitivity response and carrageenan-induced paw edema in mice. In T lymphocytes, beta-oxa 21:3n-3 inhibited the agonist-stimulated translocation of protein kinase C-betaI and -epsilon, but not -alpha, -betaII, or -theta to a particulate fraction, and also inhibited the activation of the extracellular signal-regulated protein kinase, but not c-Jun NH(2)-terminal kinase and p38. In contrast, 22:6n-3 had no effects on these protein kinase C isozymes. The increase in antiinflammatory activity and loss of unwanted bioaction through the generation of a novel synthetic 22:6n-3 analogue provides evidence for a novel strategy in the development of anti-inflammatory agents by chemically engineering PUFA.
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PMID:A novel long chain polyunsaturated fatty acid, beta-Oxa 21:3n-3, inhibits T lymphocyte proliferation, cytokine production, delayed-type hypersensitivity, and carrageenan-induced paw reaction and selectively targets intracellular signals. 1156 17

Exposure of insulin-secreting RINm5F cells to the chemical nitric oxide donor sodium nitroprusside (SNP) resulted in apoptotic cell death, as detected by cytochrome c release from mitochondria and caspase 3 activation. SNP exposure also leads to phosphorylation and activation of enzymes involved in cellular response to stress such as signal-regulated kinase 2 (ERK2) and c-Jun NH(2)-terminal kinase 46 (JNK46). Both cytochrome c release and caspase 3 activation were abrogated in cells exposed to MEK and p38 inhibitors. Treatment of cells with the NO donors SNP, DETA-NO, GEA 5024, and SNAP resulted in phosphorylation of the antiapoptotic protein Bcl-2, which was resistant to blockade of MEK, p38, and JNK pathways and sensitive to phosphoinositide 3-kinase (PI3K) inhibition. In addition, transient transfection of cells with the wild-type PI3K gamma gene mimics the increased rate of Bcl-2 phosphorylation detected in NO-treated cells. The generation of phosphoinositides seems to participate in the process since Bcl-2 phosphorylation was not observed in cells overexpressing lipid-kinase-deficient PI3Kgamma. The potential of SNP toxicity directly from NO was supported by our finding that the NO scavenger carboxy-PTIO prevented cell death. We found no evidence to support the contention that oxygen radicals generated during cellular SNP metabolism mediate cell toxicity in RINm5F cells, since neither addition of catalase/superoxide dismutase nor transfection with superoxide dismutase prevented SNP-induced cell death. Thus, we propose that exposure to apoptotic concentrations of NO triggers ERK- and p38-dependent cytochrome c release, caspase 3 activation, and PI3K-dependent Bcl-2 phosphorylation.
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PMID:Sodium nitroprusside-induced mitochondrial apoptotic events in insulin-secreting RINm5F cells are associated with MAP kinases activation. 1157 Aug 14

Several effects of the proinflammatory cytokine, interleukin-1 beta (IL-1 beta), have been described in the central nervous system, and one area of the brain where marked changes have been reported is the hippocampus. Among these changes are an IL-1 beta-induced inhibition of long term potentiation (LTP) in perforant path-granule cell synapses and an attenuation of glutamate release in synaptosomes prepared from the hippocampus. Evidence suggests that, at least in circulating cells, the anti-inflammatory cytokine, IL-10, antagonizes certain effects of IL-1. We investigated the effect of IL-10 on IL-1 beta-induced inhibition of LTP and glutamate release. The evidence presented indicates that IL-1 beta stimulates the stress-activated protein kinase, c-Jun-activated protein kinase (JNK), and IL-1 receptor-associated kinase, which may explain its inhibitory effect on release and LTP, and that IL-10 reversed the IL-1 beta-induced stimulation of JNK activity and inhibition of release and LTP. We observed that IL-10 abrogated the stimulatory effect of IL-1 beta on superoxide dismutase activity and reactive oxygen species production, whereas the H(2)O(2)-induced inhibition of LTP was also blocked by IL-10. We present evidence that suggests that the action of IL-10 may be mediated by its ability to induce shedding of the IL-1 type I receptor.
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PMID:The anti-inflammatory cytokine, interleukin (IL)-10, blocks the inhibitory effect of IL-1 beta on long term potentiation. A role for JNK. 1158 Dec 75

Chemokine expression is associated with reperfusion of infarcted myocardium in the setting of tissue necrosis, intense inflammation, and inflammatory cytokine release. The specific synthesis of monocyte chemotactic protein (MCP)-1 mRNA by cardiac venules in reperfused infarcts corresponded to the region where leukocytes normally localize. MCP-1 could be induced by exogenous tumor necrosis factor (TNF)-alpha or by postischemic cardiac lymph containing TNF-alpha. However, the release of TNF-alpha during early reperfusion did not explain the venular localization of MCP-1 induction. To better understand the factors mediating MCP-1 induction, we examined the role of ischemia/reperfusion in a model of brief coronary occlusion in which no necrosis or inflammatory response is seen. Adult mongrel dogs were subjected to 15 minutes of coronary occlusion and 5 hours of reperfusion. Ribonuclease protection assay revealed up-regulation of MCP-1 mRNA only in ischemic segments of reperfused canine myocardium. Pretreatment with the reactive oxygen scavenger N-(2-mercaptopropionyl)-glycine completely inhibited MCP-1 induction. In situ hybridization localized MCP-1 message to small venular endothelium in ischemic areas without myocyte necrosis. Gel shift analysis of nuclear extracts from the ischemic area showed enhanced DNA binding of the transcription factors AP-1 and nuclear factor (NF)-kappaB, crucial for MCP-1 expression, in ischemic myocardial regions. Immunohistochemical staining demonstrated reperfusion-dependent nuclear translocation of c-Jun and NF-kappaB (p65) in small venular endothelium, only in the ischemic regions of the myocardium, that was inhibited by N-(2-mercaptopropionyl)-glycine. In vitro, treatment of cultured canine jugular vein endothelial cells with the reactive oxygen intermediate H2O2 induced a concentration-dependent increase in MCP-1 mRNA levels, which was inhibited by the antioxidant N-acetyl-L-cysteine, a precursor of glutathione, but not pyrrolidine dithiocarbamate, an inhibitor of NF-kappaB and activator of AP-1. In contrast to our studies with infarction, incubation of canine jugular vein endothelial cells with postischemic cardiac lymph did not induce MCP-1 mRNA expression suggesting the absence of cytokine-mediated MCP-1 induction after a sublethal ischemic period. These results suggest that reactive oxygen intermediate generation, after a brief ischemic episode, is capable of inducing MCP-1 expression in venular endothelium through AP-1 and NF-kappaB. Short periods of ischemia/reperfusion, insufficient to produce a myocardial infarction, induce MCP-1 expression, potentially mediating angiogenesis in the ischemic noninfarcted heart.
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PMID:Reactive oxygen intermediates induce monocyte chemotactic protein-1 in vascular endothelium after brief ischemia. 1158 58

cis-platinum(II) (cis-diammine dichloroplatinum; cisplatin) is a potent antitumor compound that is widely used for the treatment of many malignancies. An important side-effect of cisplatin is nephrotoxicity, which results from injury to renal tubular epithelial cells and can be manifested as either acute renal failure or a chronic syndrome characterized by renal electrolyte wasting. Recently, apoptosis has been recognized as an important mechanism of cell death mediating the antitumor effect of cisplatin. This study was undertaken to examine the mechanisms of cell death induced by cisplatin in M-1 cells, which were derived from the outer cortical collecting duct cells of SV40 transgenic mice. Treatment of M-1 cells with high concentrations of cisplatin (0.5 and 1 mM) for 2 hr led to necrotic cell death, whereas a 24-hr treatment with 5-20 microM cisplatin led to apoptosis. Antioxidants protected against cisplatin-induced necrosis, but not apoptosis, indicating that reactive oxygen species play a role in mediating necrosis but not apoptosis induced by cisplatin and that the mechanism of cell death induced by cisplatin is concentration dependent. The low concentrations of cisplatin, which induced apoptosis in M-1 cells, did not affect the expression levels of Bcl-2-related proteins and did not activate c-Jun NH2-terminal kinase (SAPK/JNK). Cisplatin induced the translocation of endogenous Bax from the cytosolic to the membrane fractions and, subsequently, the release of cytochrome c. Overexpression of Bcl-2 blocked cisplatin-induced apoptosis and Bax translocation. These observations suggest that the subcellular redistribution of Bax is a critical event in the apoptosis induced by cisplatin.
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PMID:Cisplatin-induced apoptosis by translocation of endogenous Bax in mouse collecting duct cells. 1159 70

Bursts in reactive oxygen species production are important mediators of contractile dysfunction during ischemia-reperfusion injury. Cellular mechanisms that mediate reactive oxygen species-induced changes in cardiac myocyte function have not been fully characterized. In the present study, H(2)O(2) (50 microM) decreased contractility of adult rat ventricular myocytes. H(2)O(2) caused a concentration- and time-dependent activation of extracellular signal-regulated kinases 1 and 2 (ERK1/2), p38, and c-Jun NH(2)-terminal kinase (JNK) mitogen-activated protein (MAP) kinases in adult rat ventricular myocytes. H(2)O(2) (50 microM) caused transient activation of ERK1/2 and p38 MAP kinase that was detected as early as 5 min, was maximal at 20 min (9.6 +/- 1.2- and 9.0 +/- 1.6-fold, respectively, vs. control), and returned to baseline at 60 min. JNK activation occurred more slowly (1.6 +/- 0.2-fold vs. control at 60 min) but was sustained at 3.5 h. The protein kinase C inhibitor chelerythrine completely blocked JNK activation and reduced ERK1/2 and p38 activation. The tyrosine kinase inhibitors genistein and PP-2 blocked JNK, but not ERK1/2 and p38, activation. H(2)O(2)-induced Na(+)/H(+) exchanger phosphorylation was blocked by the MAP kinase kinase inhibitor U-0126 (5 microM). These results demonstrate that H(2)O(2)-induced activation of MAP kinases may contribute to cardiac myocyte dysfunction during ischemia-reperfusion.
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PMID:Differential MAP kinase activation and Na(+)/H(+) exchanger phosphorylation by H(2)O(2) in rat cardiac myocytes. 1160 Apr 17

Early chemokine induction in the area at risk of an ischemic-reperfused (I/R) myocardium is first seen in the venular endothelium. Reperfusion is associated with several induction mechanisms including increased extracellular tumor necrosis factor (TNF)-alpha, reactive oxygen intermediate (ROI) species formation, and adhesion of leukocytes to the venular endothelium. To test the hypothesis that chemokine induction in cardiac venules can occur by ROIs in a TNF-alpha-independent manner, and in the absence of leukocyte accumulation, we utilized wild-type (WT) and TNF-alpha double-receptor knockout mice (DKO) in a closed-chest mouse model of myocardial ischemia (15 min) and reperfusion (3 h), in which there is no infarction. We demonstrate that a single brief period of I/R induces significant upregulation of the chemokines macrophage inflammatory protein (MIP) -1 alpha, -1 beta, and -2 at both the mRNA and protein levels. This induction was independent of TNF-alpha, whereas levels of these chemokines were increased in both WT and DKO mice. Chemokine induction was seen predominantly in the endothelium of small veins and was accompanied by nuclear translocation of nuclear factor-kappa B and c-Jun (AP-1) in venular endothelium. Intravenous infusion of the oxygen radical scavenger N-2-mercaptopropionyl glycine (MPG) initiated 15 min before ischemia and maintained throughout reperfusion obviated chemokine induction, but MPG administration after reperfusion had begun had no effect. The results suggest that ROI generation in the reperfused myocardium rapidly induces C-C and C-X-C chemokines in the venular endothelium in the absence of infarction or irreversible cellular injury.
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PMID:Brief murine myocardial I/R induces chemokines in a TNF-alpha-independent manner: role of oxygen radicals. 1170 22

Oxidized low-density lipoprotein (oxLDL) is known to activate a number of signal transduction pathways in endothelial cells. Among these are the c-Jun NH(2)-terminal kinase (JNK), also known as stress-activated protein kinase, and extracellular signal-regulated kinase (ERK). These mitogen-activated protein kinases (MAP kinase) determine cell survival in response to environmental stress. Interestingly, JNK signaling involves redox-sensitive mechanisms and is activated by reactive oxygen and nitrogen species derived from both NADPH oxidases, nitric oxide synthases (NOS), peroxides, and oxidized low-density lipoprotein (oxLDL). The role of endothelial NOS (eNOS) in the activation of JNK in response to oxLDL has not been examined. Herein, we show that on exposure of endothelial cells to oxLDL, both ERK and JNK are activated through independent signal transduction pathways. A key role of eNOS activation through a phosphatidylinositol-3-kinase-dependent mechanism leading to phosphorylation of eNOS is demonstrated for oxLDL-dependent activation of JNK. Moreover, we show that activation of ERK by oxLDL is critical in protection against the cytotoxicity of oxLDL.
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PMID:Endothelial NOS-dependent activation of c-Jun NH(2)- terminal kinase by oxidized low-density lipoprotein. 1170 40

Under low-oxygen conditions, cells develop an adaptive program that leads to the induction of several genes, which are transcriptionally regulated by hypoxia-inducible factor 1 (HIF-1). On the other hand, there are other factors which modulate the HIF-1-mediated induction of some genes by binding to cis-acting motifs present in their promoters. Here, we show that c-Jun functionally cooperates with HIF-1 transcriptional activity in different cell types. Interestingly, a dominant-negative mutant of c-Jun which lacks its transactivation domain partially inhibits HIF-1-mediated transcription. This cooperative effect is not due to an increase in the nuclear amount of the HIF-1alpha subunit, nor does it require direct binding of c-Jun to DNA. c-Jun and HIF-1alpha are able to associate in vivo but not in vitro, suggesting that this interaction involves the participation of additional proteins and/or a posttranslational modification of these factors. In this context, hypoxia induces phosphorylation of c-Jun at Ser(63) in endothelial cells. This process is involved in its cooperative effect, since specific blockade of the JNK pathway and mutation of c-Jun at Ser(63) and Ser(73) impair its functional cooperation with HIF-1. The functional interplay between c-Jun and HIF-1 provides a novel insight into the regulation of some genes, such as the one for VEGF, which is a key regulator of tumor angiogenesis.
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PMID:c-Jun and hypoxia-inducible factor 1 functionally cooperate in hypoxia-induced gene transcription. 1173 18

In retinitis pigmentosa, retinal detachment, age-related macular degeneration, and glaucoma, retinal neuronal cells are damaged by a common mechanism, apoptosis. Because apoptosis is an active process that requires de novo expression of a "death message", this process can be controlled by inhibiting the expression of the "death message". We first studied whether a retinal ischemia-reperfusion model can be used as a model for retinal neuronal apoptosis. In the retinal ischemia-reperfusion injuries, typical features of apoptosis, including TUNEL-positive cells, DNA ladder formation, and ultrastructural features of apoptosis were found. Using the model, systematic research to identify the "death message" was done by DNA microarray analysis. About 200 messages were found to be up- or down-regulated during the process of retinal ischemia-reperfusion. These genes were divided into four groups: (1) transcription factor genes, (2) cell cycle-related genes, (3) reactive oxygen scavenger genes and (4) molecular chaperon genes. The possible roles of such genes in neuronal apoptosis following retinal ischemia-reperfusion injury were studied. In the model, reactive oxygen species produced by reperfusion was found to generate lipid peroxides and induced up-regulation of a transcription factor, c-Jun, that further induced aberrant expression of cell cycle-related genes such as cyclin D1 in amacrine cells. However, because no controlled expression of cell cycle-related genes takes place in retinal neurons, amacrine cells died by a G1 arrest mechanism. On the other hand, horizontal cells never expressed cyclin D1 and the cells were found to die by necrosis. The study revealed a possible mechanism of retinal neuronal apoptosis and it also became apparent that different types of neurons use different "death messages". Furthermore, the possibility that inhibition of a "death message" sometimes induces necrosis rather than apoptosis was shown. This means that we need to try inhibition of the death mechanism upstream rather than downstream. Administration of thioredoxin, an endogenous reactive oxygen species that blocks generation of lipid peroxides and thus inhibits the death process upstream, was found to be neuroprotective against retinal ischemia-reperfusion injury. Aberrant expression of c-Jun and cyclin D1 was down-regulated by the treatment. Possible roles of caspases were also studied by using the ischemia-reperfusion injury, RCS rat, and excessive light exposure damage in wild type and caspase-1 deficient mice. Also, application of adeno-associated virus that carries Bcl-xL was tested to find possible neuroprotective effects on RCS rats. Our studies showed that caspase-1 played a more important role in the retinal photoreceptors and caspase-3 was important in neurons in the inner nuclear layer. Caspase-2 was found to be a major caspase in the retinal ganglion cell layer. In agreement with the findings, caspase-1 deficient mice showed less prominent light damage than wild type mice. Gene therapy by Bcl-xL was effective to protect retinal photoreceptor damage in RCS rats.
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PMID:[Retinal neuronal cell death: molecular mechanism and neuroprotection]. 1180 59


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