Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0017638 (glioma)
 30,880 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

1. This study investigated the effects of acute and chronic ethanol on basal, agonist- and forskolin-stimulated cyclic AMP formation in NG108-15 mouse neuroblastoma x rat glioma hybrid cells, and examined the role of changes in extracellular adenosine concentrations on the effects observed. 2. NG108-15 cells incubated acutely with ethanol (1-200 mM) displayed concentration-dependent increases in basal and iloprost-stimulated (300 nM; a prostanoid IP receptor agonist) cyclic AMP accumulation but a concentration-dependent decrease in forskolin-stimulated (10 microM) accumulation. 3. Cells treated chronically with ethanol (200 mM) for 48 h displayed increases over control in basal, iloprost- (0.001-10 microM) and forskolin (0.01-100 microM)-stimulated cyclic AMP formation. However, chronic ethanol did not affect [3H]-iloprost binding to cell membranes. 4. Inclusion of adenosine deaminase (ADA; 1 unit ml-1) during the incubation period to measure cyclic AMP accumulation completely abolished the increase in basal accumulation following chronic ethanol, but did not affect the increase in iloprost stimulation. On the other hand ADA partially reversed the increase in forskolin stimulation following chronic ethanol, but even in the presence of high concentrations of ADA (5 units ml-1) the forskolin stimulation remained elevated above control. 5. Cells treated chronically with the adenosine receptor agonist 5'-(N-ethylcarboxamido)-adenosine (NECA; 10 microM for 48 h) displayed a reduction in subsequent NECA- and forskolin-stimulated cyclic AMP accumulation, but iloprost stimulation was not affected. ADA included acutely during the incubation period to measure cyclic AMP accumulation abolished the reduction in forskolin but not NECA stimulation produced by the chronic NECA pretreatment. 6. We have previously noted that ethanol inhibits NG108-15 cell proliferation and alters cell morphology.To mimic this, cells were incubated in the absence of foetal calf serum for 48 h. Following this time, basal, iloprost- and forskolin-stimulated cyclic AMP formation was enhanced over that in cells grown in the presence of serum.7. These results indicate that chronic ethanol enhances cyclic AMP formation in intact NG108-15 cells by more than one mechanism: one involves increased extracellular adenosine concentrations and the other a change in the transduction system beyond the receptor, possibly involving the adenylyl cyclase enzyme. Furthermore the ethanol-induced changes in cyclic AMP accumulation may relate to alterations in NG108-15 cell growth and development.
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PMID:Effects of acute and chronic ethanol on cyclic AMP accumulation in NG108-15 cells: differential dependence of changes on extracellular adenosine. 754 91

In the presence of substance P (SP; 10 microM), serotonin (5-HT; 1 microM) triggered a cation permeability in cells of the hybridoma (mouse neuroblastoma x rat glioma) clone NG 108-15 that could be assessed by measuring the cell capacity to accumulate [14C]guanidinium for 10-15 min at 37 degrees C. In addition to 5-HT (EC50 0.33 microM), the potent 5-HT3 receptor agonists 2-methyl-serotonin, phenylbiguanide, and m-chlorophenylbiguanide, and quipazine, markedly increased [14C]guanidinium uptake in NG 108-15 cells exposed to 10 microM SP. In contrast, 5-HT3 receptor antagonists prevented the effect of 5-HT. The correlation (r = 0.97) between the potencies of 16 different ligands to mimic or prevent the effects of 5-HT on [14C]guanidinium uptake, on the one hand, and to displace [3H]zacopride specifically bound to 5-HT3 receptors on NG 108-15 cells, on the other hand, clearly demonstrated that [14C]guanidinium uptake was directly controlled by 5-HT3 receptors. Various compounds such as inorganic cations (La3+, Mn2+, Ba2+, Ni2+, and Zn2+), D-tubocurarine, and memantine inhibited [14C]guanidinium uptake in NG 108-15 cells exposed to 5-HT and SP, as expected from their noncompetitive antagonistic properties at 5-HT3 receptors. However, ethanol (100 nM), which has been reported to potentiate the electrophysiological response to 5-HT3 receptor stimulation, prevented the effects of 5-HT plus SP on [14C]guanidinium uptake. The cooperative effect of SP on this 5-HT3-evoked response resulted neither from an interaction of the peptide with the 5-HT3 receptor binding site nor from a possible direct activation of G proteins in NG 108-15 cells. Among SP derivatives, [D-Pro9]SP, a compound inactive at the various neurokinin receptor classes, was the most potent to mimic the stimulatory effect of SP on [14C]guanidinium uptake in NG 108-15 cells exposed to 5-HT. Although the cellular mechanisms involved deserve further investigations, the 5-HT-evoked [14C]guanidinium uptake appears to be a rapid and reliable response for assessing the functional state of 5-HT3 receptors in NG 108-15 cells.
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PMID:Characteristics of [14C]guanidinium accumulation in NG 108-15 cells exposed to serotonin 5-HT3 receptor ligands and substance P. 768 66

Human neuroblastoma cells SH-SY5Y and neuroblastoma-glioma cells NG 108-15 have been used as models for the elucidation of the effects of ethanol on receptor-mediated phospholipase C activity, c-fos mRNA expression and protein kinase C activity. Cells were exposed to ethanol (0-200 mM) for varying periods up to seven days. Agonist stimulated events were obtained in NG 108-15 cells with bradykinin and in SH-SY5Y cells with carbachol. Chronic ethanol exposure reduced the agonist-stimulated formation of inositol 1,4,5-trisphosphate in NG 108-15 cells and in SH-SY5Y cells. 100 mM ethanol for seven days increased the membrane bound and cytosolic forms of protein kinase C activity in SH-SY5Y cells. Carbachol (1 mM) induced a maximal c-fos mRNA response after 40 minutes in SH-SY5Y cells, an effect that could be mimicked through protein kinase C stimulation by phorbol esters.
Alcohol Alcohol Suppl 1993
PMID:Evaluation of ethanol effects on PLC signal transduction pathways using cell lines of neuronal origin. 774 14

Acute ethanol treatment of NG108-15 neuroblastoma x glioma hybrid cells results in inhibition of adenosine uptake with consequent increases in extracellular adenosine and intracellular cAMP concentrations. Chronic exposure to ethanol, however, causes heterologous desensitization of receptors coupled to adenylyl cyclase via stimulatory guanine nucleotide regulatory protein. This heterologous desensitization is correlated with a decrease in the amount of protein and mRNA for the GTP-binding subunit of stimulatory guanine nucleotide regulatory protein. In addition, after chronic exposure to ethanol, the adenosine transporter becomes tolerant to acute ethanol inhibition of adenosine uptake, and there is no longer an increase in extracellular adenosine. We have previously shown that extracellular adenosine is required for the development of ethanol-induced heterologous desensitization. To examine the role of adenosine receptors in mediating these responses to ethanol, we used BW A1434U, an adenosine receptor antagonist that does not inhibit nucleoside transport. BW A1434U caused a concentration-dependent inhibition of (-)-N6-(R-phenyl-isopropyl)-adenosine-stimulated cAMP production in NG108-15 cells. BW A1434U also completely blocked acute ethanol-induced increases in intracellular cAMP levels and prevented the development of ethanol-induced heterologous desensitization and the reduction in the GTP-binding subunit of stimulatory guanine nucleotide regulatory protein. In addition, BW A1434U prevented the development of tolerance to ethanol-induced inhibition of adenosine transport. Our results indicate that in NG108-15 cells, adenosine receptors mediate ethanol-induced changed in cAMP signal transduction and adenosine transport and that an adenosine receptor antagonist can block both these acute and chronic affects of ethanol.
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PMID:Adenosine receptors mediate cellular adaptation to ethanol in NG108-15 cells. 796 54

Previously we found that ethanol increases expression of the constitutive 70-kDa heat shock protein (Hsc70) in NG108-15 neuroblastoma x glioma cells. We suggested that known ethanol actions on cellular protein trafficking may relate to Hsc70 induction because Hsc70 functions as a molecular chaperone. Here we use a subtractive hybridization protocol to isolate ethanol-responsive genes (EtRGs). Northern blot hybridization verified ethanol-induced increases in mRNA abundance for five cDNA clones isolated from ethanol-treated NG108-15 neuroblastoma x glioma cells. DNA sequence analysis identified one EtRG as 94-kDa glucose-regulated protein (GRP94), a member of the "glucose-responsive" subgroup of stress proteins. Other identified EtRGs included an insulin-induced growth-response protein gene and an intracisternal A-type particle gene. Sequence analysis of the remaining two EtRGs showed no homology in DNA sequence databases. All EtRGs showed wide tissue expression, except SL64, which was not detected in Northern blot analyses of adult mouse or rat tissues. Ethanol also increased mRNA abundance for 78-kDa glucose-regulated protein (GRP78), a molecular chaperone known to function in glycoprotein trafficking and usually coordinately regulated with GRP94. However, ethanol induced GRP94 more than GRP78, a pattern distinct from those of other inducers of these genes. All EtRGs, including GRP94 and GRP78, showed similar ethanol concentration-dependent increases in mRNA abundance. In contrast, thapsigargin and other inducers of glucose-responsive proteins increased GRP94 and GRP78 mRNA levels without altering expression of other EtRGs. Our studies demonstrate that several molecular chaperones constitute a subset of EtRGs. Ethanol appears to regulate these EtRGs by a unique mechanism, rather than one shared by classical inducers of stress proteins.
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PMID:Ethanol-responsive genes in neural cells include the 78-kilodalton glucose-regulated protein (GRP78) and 94-kilodalton glucose-regulated protein (GRP94) molecular chaperones. 796 74

Effect of long-term exposure to ethanol (EtOH) on the phosphatidylinositol 4,5-biphosphate (PIP2)-specific and cytosolic phospholipase C (PLC) activities in neuroblastoma x glioma hybrid (NG 108-15) cells and the brains from EtOH-inhaled mice were investigated. Long-term (2 days) exposure of NG 108-15 cells to EtOH induced significant decrease in PIP2-specific PLC activity dependent on concentration and duration of exposure, although the presence of EtOH in the enzyme assay system induced no alteration in PIP2-specific PLC activity. On the other hand, cytosolic PLC activity in NG 108-15 cells significantly increased by both the long-term exposure of the cells to EtOH and the addition of EtOH into the assay system. These changes in activities of both types of PLC in NG 108-15 cells observed after EtOH exposure recovered rapidly by the removal of EtOH. Moreover, the changes in activities of PIP2-specific and cytosolic PLC in the brain of EtOH-inhaled mice were similar to those found in NG 108-15 cells. These results indicate that EtOH inhibits the activity of PIP2-specific PLC and activates cytosolic PLC in the brain. These changes in cerebral PLC activities are suggested to involve in central action of EtOH and establishment of alcohol dependence.
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PMID:Ethanol-induced alteration in activities of cerebral phosphatidylinositol 4,5-biphosphate-specific and cytosolic phospholipase C in the brain: analysis using NG 108-15 cells and brains from ethanol-inhaled mice. 798 35

Our studies in the NG108-15 neuroblastoma x glioma cell line previously showed that the molecular chaperonin, Hsc70, is an ethanol-responsive gene (EtRG) regulated at the level of transcription by ethanol. We recently identified two related molecular chaperonins, GRP94 and GRP78, as EtRGs with GRP94 mRNA abundance being induced by ethanol more than three-fold vs. control. Stable transfection studies show that GRP78 transcription is also regulated by ethanol and that ethanol also potentiates GRP78 induction by classical inducing agents such as tunicamycin. Recently, we have found that ethanol induction of Hsc70 may require cis-acting promoter sequences recognized by the DNA-binding protein Sp1. Chronic ethanol exposure does not alter Sp1 DNA-binding activity, thus suggesting a possible ethanol-induced post-translational modification that activates Sp1 function. We predict that the molecular mechanisms underlying ethanol regulation of Hsc70, GRP94 and GRP78 may be similar since they have related functions. GRP94 and GRP78 (GRP94/78) are known to be induced by agents which inhibit glycoprotein processing or deplete endoplasmic reticulum stores of calcium. In turn, induction of GRP78 expression is known to selectively alter the transport of glycoproteins and produce "tolerance" to depletion of sequestered intracellular calcium. The regulation of these genes by ethanol could thus relate to the known effects of ethanol on calcium homeostasis and protein trafficking. The actions of ethanol on chaperonin gene expression may have important mechanistic implications for CNS adaptation to ethanol, particularly if other EtRGs share the same regulatory mechanisms.
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PMID:Effects of alcohol on gene expression in neural cells. 803 72

Elevation of cAMP changes the morphology of C6 rat glioma cells from a fibroblast to an astrocyte type of appearance. This change is prevented by the presence of serum from different species (chicken, mouse, rat, horse, adult bovine, fetal bovine, and human) in the cell culture medium. In this communication the component in serum responsible for this effect is identified as lysophosphatidic acid for the following reasons: First, lysophosphatidic acid alone at concentrations which are present in serum reverts the morphological response. Second, both lysophosphatidic acid and the component in serum no longer revert the morphological response after treatment with phospholipase B (E.C.3.1.1.5). Third, lysophosphatidic acid and serum produce an analogous intracellular Cai2+ signal in rat glioma C6 cells as measured by fluorescence spectrophotometry with the Ca2+ ion indicator Fura 2. Fourth, both the morphological response and the Cai2+ increase are prevented by pretreatment of the cells with 100 ng/ml phorbol 12-myristate 13-acetate. Finally, a maximal Cai2+ increase induced by FCS prevents the subsequent Cai2+ signal by lysophosphatidic acid. Interestingly, the morphological response is also reverted by Al3+ together with F- ions and also by lower n-alkanols such as ethanol and n-propanol suggesting that a regulatory GTP-binding protein is involved in the reversion. It is further shown that activation of the phosphatidylinositol 4,5-bisphosphate cleavage signal system is not responsible for the reversion of the morphological response.
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PMID:Lysophosphatidic acid reverts the beta-adrenergic agonist-induced morphological response in C6 rat glioma cells. 809 26

Gestational exposure to ethanol causes defects in neuronal migration, fasciculation, and synaptogenesis, developmental events that depend on the patterned expression and function of cell adhesion molecules (CAMs). Recombinant human osteogenic protein-1 (hOP-1) increases cell-cell adhesion and promotes cell clustering in proliferating neuroblastoma x glioma hybrid NG108-15 cells by strongly inducing N-CAM and L1. Here we show that concentrations of ethanol achieved during social drinking inhibit hOP-1-induced cell clustering without affecting cell proliferation, the induction and cell surface expression of N-CAM and L1, or the alternative splicing and sialylation of N-CAM. This inhibition was reproduced by other alcohols in proportion to their chain length, but not by teratogenic anticonvulsants or phenylalanine. Ethanol inhibition of hOP-1 morphogenesis was inversely proportional to the concentration of hOP-1 and, hence, to the levels of N-CAM and L1. Low concentrations of ethanol (IC50 5-10 mM) inhibited cell-cell adhesion in hOP-1-treated cells, and this action too was reproduced more potently by propanol and butanol. Ethanol may perturb brain and skeletal development by inhibiting CAM-mediated cell-cell interactions.
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PMID:Ethanol inhibits neural cell-cell adhesion. 813 68

Long-term treatment with ethanol increases delta-opioid receptor (DOR) expression in the NG108-15 neuroblastoma x glioma hybrid cell line. To determine the underlying mechanism, we studied the effects of ethanol on [3H]diprenorphine binding to intact cells and DOR gene expression in four related clonal neural cell lines. Incubation with 200 mM ethanol for 48 hr increased [3H]diprenorphine binding by 1.4- (N18TG2), 1.8- (NG108-15), 1.9- (N4TG1), and 3.0-fold (N1E-115). Treatment with 25, 50, or 100 mM ethanol for 1 week caused a dose-dependent increase in receptor expression. Receptor up-regulation was associated with an increase in the potency of etorphine for inhibiting prostaglandin E1-stimulated cAMP accumulation. Constitutive DOR expression differed more than 3-fold among the different cell lines and correlated positively with basal cAMP levels. Long-term ethanol treatment increased basal cAMP levels in three of the four cell lines, but did not induce cellular differentiation. Northern blot analysis demonstrated an identical pattern of multiple transcripts in the four cell lines. Ethanol increased the abundance of DOR mRNA by approximately 3-fold in N18TG2 cells and by approximately 5-fold in the remaining cell lines. These findings indicate that clinically relevant concentrations of ethanol regulate DOR expression by increasing the abundance of DOR mRNA. The disparity between the increase in gene expression and ligand binding suggests that ethanol may also modify mRNA translation or receptor processing.
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PMID:Ethanol increases delta-opioid receptor gene expression in neuronal cell lines. 826 48


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