Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027819 (neuroblastoma)
 27,800 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In SK-N-SH human neuroblastoma cells, the muscarinic agonist carbachol promotes polyphosphoinositide (PPI) hydrolysis via M3 receptors and increases cyclic AMP levels through an unidentified mechanism. Activation of PPI hydrolysis by carbachol elicits a robust translocation of CaM from membranes into cytosol which was previously shown to be mimicked by the addition of the calcium ionophore ionomycin and the phorbol ester TPA28. The effect of agonist-stimulated second messenger production on CaM localization was determined by activating receptors that increase and decrease adenylyl cyclase activity on SK-N-SH cells. VIP (10 microM), prostaglandin E1 (30 microM) and forskolin (10 microM) all increased adenylyl cyclase activity 8- to 10-fold above the activity with 1 microM GTP. Carbachol (100 microM) did not stimulate adenylyl cyclase activity. The alpha 2-adrenergic agonist UK 14,304 (0.1 microM) and the delta and mu opioid DPDPE (10 microM) and DAMGO (10 microM) inhibited forskolin-stimulated cyclic AMP formation by 27-32%. CaM did not stimulate adenylyl cyclase activity. Incubation of cells with vasoactive intestinal polypeptide (VIP), dibutyryl cyclic AMP and forskolin, resulted in 30% decrease in membrane CaM and an increase in cytosolic CaM of 40-50%. The CaM translocation with the combination of an agent that elevates cyclic AMP levels and a low dose of carbachol was not different from that observed with either agent alone. UK 14,304, DPDPE and DAMGO potentiated carbachol-stimulated increases in cytosolic CaM. Upon the addition of carbachol, a 5-fold increase in intracellular calcium concentration measured with fura-2 fluorescence was observed. VIP and UK 14,304 elevated intracellular calcium concentrations 2 to 3 fold, while forskolin (10 microM) had no effect.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Cyclic AMP accumulation alters calmodulin localization in SK-N-SH human neuroblastoma cells. 134 31

Parameters of ligand binding, stimulation of low-Km GTPase, and inhibition of adenylate cyclase were determined in intact human neuroblastoma SH-SY5Y cells and in their isolated membranes, both suspended in identical physiological buffer medium. In cells, the mu-selective opioid agonist [3H]Tyr-D-Ala-Gly(Me)Phe-Gly-ol ([3H]DAMGO) bound to two populations of sites with KD values of 3.9 and 160 nM, with less than 10% of the sites in the high-affinity state. Both sites were also detected at 4 degrees C and were displaced by various opioids, including quaternary naltrexone. The opioid antagonist [3H]naltrexone bound to a single population of sites, and in cells treated with pertussis toxin the biphasic displacement of [3H]naltrexone by DAMGO became monophasic with only low-affinity binding present. The toxin specifically reduced high-affinity agonist binding but had no effect on the binding of [3H]naltrexone. In isolated membranes, both agonist and antagonist bound to a single population of receptor sites with affinities similar to that of the high-affinity binding component in cells. Addition of GTP to membranes reduced the Bmax for [3H]DAMGO by 87% and induced a linear ligand binding component; a low-affinity binding site, however, could not be saturated. Compared with results obtained with membranes suspended in Tris buffer, agonist binding, including both receptor density and affinity, in the physiological medium was attenuated. The results suggest that high-affinity opioid agonist binding represents the ligand-receptor-guanine nucleotide binding protein (G protein) complex present in cells at low density due to modulation by endogenous GTP.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Opioid signal transduction in intact and fragmented SH-SY5Y neural cells. 156 Feb 22

In previous studies, we have demonstrated that chronic treatment of rats with either etorphine or D-Ala2, D-Leu5-enkephalin (DADLE) resulted in the reduction of opioid receptor binding activities during the course of tolerance development. In both cases, mu-opioid receptor binding capacity was attenuated together with the delta-opioid receptor binding capacity. Because both etorphine and DADLE are relatively non-specific opioid ligands, interacting with both mu and delta receptors, these studies could not determine whether down-regulation of a specific receptor type is possible. Therefore, in the current studies, animals were rendered tolerant to the mu-opioid receptor-selective ligand PL017 and the receptor binding capacity was measured afterwards. Treating Sprague-Dawley rats with increasing doses of PL017 (2.5-20 micrograms/kg) i.c.v. for 5 days resulted in a 30- to 40-fold increase in the AD50 of the peptide to elicit the antinociceptive response and about 14-fold increase in the ED50 of the peptide to elicit the catatonic effect. When mu- and delta-binding was determined using [3H]diprenorphine in the presence of morphiceptin or DPDPE respectively, a significant decrease (20-30%) in the mu-opioid receptor binding but not in delta-opioid receptor binding was observed in all the brain areas tested after 5 days of PL017 treatment. Scatchard analysis of the [3H]DAMGO saturation binding data revealed a decrease in Bmax values and no change in the Kd values. Hence, mu-opioid receptors can be specifically regulated by ligand in the brain as delta-receptors are in neuroblastoma x glioma NG 108-15 cells.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Decrease in mu-opioid receptor binding capacity in rat brain after chronic PL017 treatment. 217 41

The irreversible opioid receptor antagonists naloxonazine and beta-funaltrexamine have been used to determine whether multiple mu-opioid receptors exist on undifferentiated SH-SY5Y human neuroblastoma cells. Naloxonazine binds irreversibly to the mu 1-opioid receptor subtype and reversibly to the mu 2-opioid receptor subtype. On SH-SY5Y cells naloxonazine afforded a Ki of 3.4 +/- 0.7 nM, and was fully reversible, indicating the mu-opioid receptor population on SH-SY5Y cells was solely of the mu 2-opioid receptor subtype. The alkylating agent beta-funaltrexamine was maximally able to alkylate only 60% of the mu-opioid receptor sites on SH-SY5Y cells, labelled with [3H]diprenorphine or [3H][D-Ala2,MePhe4,Gly(ol)5]enkephalin (DAMGO). The reversible binding of naloxonazine and the insensitivity of a percentage of the mu-opioid receptor sites to alkylation by beta-funaltrexamine suggests that differences do exist in the mu 2-opioid receptor population on undifferentiated SH-SY5Y cells. This may indicate further heterogeneity or the inability of beta-funaltrexamine to alkylate all relevant nucleophilic groups in a single population of receptors.
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PMID:Characterisation of mu-opioid receptors on SH-SY5Y cells using naloxonazine and beta-funaltrexamine. 780 71

Total opioid binding in the human neuroblastoma cell line BE(2)-C has a density similar to that found in brain, with a Bmax value of 383 +/- 60 fmol/mg protein and a KD of 0.4 +/- 0.07 nM for the nonselective opioid antagonist 3H-diprenorphine. Selective assays reveal a binding distribution of mu (38%), delta (16%) and kappa 3 (43%) opioid receptors. There is no observable kappa 1 or kappa 2 binding. The sum of the Bmax values in the selective binding assays (370 +/- 39 fmol/mg protein) approximates closely that observed with 3H-diprenorphine, suggesting that mu, delta and kappa 3 sites account for most of the binding. The binding selectivities of various opiates and opioid peptides in the BE(2)-C cells are similar to those in rat brain. Delta and mu binding are defined easily by traditional selective ligands. The binding profiles also distinguish clearly mu from kappa 3 binding. The selective mu ligand DAMGO competes with mu binding over 35-fold more potently than kappa 3 binding, whereas morphine shows a 10-fold selectivity. Functionally, selective mu, delta and kappa 3 agonists inhibit forskolin-stimulated cAMP accumulation through distinct receptor mechanisms that are pertussis toxin-sensitive. In addition to demonstrating that BE(2)-C cells provide a useful model system for studying mu, kappa 3 and delta receptors, these studies confirm that kappa 3 receptors represent a pharmacologically distinct receptor class in this cell line.
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PMID:Biochemical and pharmacological characterization of mu, delta and kappa 3 opioid receptors expressed in BE(2)-C neuroblastoma cells. 793 77

Both mu and delta opioid receptors are expressed in undifferentiated human neuroblastoma SHSY5Y cells and are negatively coupled to adenylate cyclase. The ability of various mu opioid, delta opioid and alpha-2 adrenergic agonists to inhibit acutely forskolin-stimulated adenylate cyclase activity in undifferentiated SHSY5Y cells after chronic administration with the selective mu opioid agonist [N-MePhe3,D-Pro4]morphiceptin (PLO17) or delta opioid agonist, [D-Pen2,D-Pen5]enkephalin (DPDPE) was assessed. In control cells, both PLO17 and DPDPE inhibited cyclic AMP (cAMP) formation with equal maximal inhibition, i.e., 60 +/- 3 and 66 +/- 2%, having IC50 values of 51.1 +/- 1.3 and 3.7 +/- 1.0 nM, respectively. The inhibition of intracellular cAMP formation by both agonists could be blocked by pertussis toxin pretreatment. After 24 hr of chronic administration of PLO17 (50 nM to 10 microM), a concentration-dependent loss of the ability of mu opioid agonists PLO17 and DAMGO, but not the delta opioid agonists DPDPE, nor alpha-2 adrenergic agonist UK-14304 (5-Bromo-N-(4,5,-dihydro-1H-imidazol-2-yl)-6-quinoxalinamine) to inhibit adenylate cyclase activity was observed. In contrast, chronic administration of DPDPE (0.1 nM to 0.3 microM) resulted in a concentration-dependent reduction in the inhibition of cAMP formation produced by delta opioid agonists DPDPE and DSLET, but not mu opioid, nor alpha-2 adrenergic agonists tested. The observed homologous desensitization was also time-dependent. In addition, antagonist-induced increases in adenylate cyclase activity were observed only after chronic PLO17 administration.2+ Finally, chronic pretreatment of cells with PLO17 (10 microM) resulted in a significant decrease in mu opioid, but not delta opioid receptor, binding, whereas treatment with DPDPE (0.3 microM) resulted in a significant decrease in delta opioid, but not mu opioid receptor binding. Therefore, undifferentiated SHSY5Y cells may provide an excellent model system to study not only the signal transduction mechanisms of mu and/or delta opioid receptors, but also the cellular adaptations of specific opioid receptors.
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PMID:Mu and delta opioid receptor desensitization in undifferentiated human neuroblastoma SHSY5Y cells. 803 14

The human neuroblastoma cell line SH-SY5Y was used to demonstrate morphine-induced down-regulation and naloxone-induced up-regulation of opiate receptors in a mu receptor containing neuronally derived preparation capable of desensitization to morphine. Chronic exposure to morphine decreased the number but not the affinity of mu opiate receptors in SH-SY5Y cells. Differentiation of the cells with retinoic acid or with the phorbol agent TPA (12-O-tetradecanoyl-phorbol-13-acetate) increased the number of mu receptors. Morphine-induced down-regulation, however, was observed in the absence of differentiation as well as after differentiation with retinoic acid or TPA. The decrease in the number of receptors was related to time of exposure, with a half-maximum disappearance time (T1/2) of about 3 hr during the initial phase. The receptor decrease was near maximum at 24 hr with no further significant change up to 72 hr. The loss of [3H] DAMGO ([3H]Tyr-D-Ala-Gly-N-Me-Phe-Gly-ol) binding was also dose-dependent, with reductions occurring at 0.3, 1 and 10 microM. The loss of receptors was dependent on temperature, with reductions at 37 but not 23 degrees C. The down-regulation was blocked by naloxone and the mu-selective antagonist CTOP (D-Phe-Cys-Tyr-D(-Trp-)Orn-Thr-Pen-Thr-NH2), but not by the delta antagonist ICI 174864 ([N,N-diallyl-Tyr1,Aib2,3]Leu-enkephalin). Cholinergic ([3H]quinclidinyl benzilate) binding was not affected by the morphine treatment, indicating that the down-regulation was homologous for opiate receptors. In SH-SY5Y cells, unlike other cell models, the opiate antagonist naloxone upregulated mu receptors by more than 50%.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Mu opiate receptor down-regulation by morphine and up-regulation by naloxone in SH-SY5Y human neuroblastoma cells. 809 44

Human neuroblastoma cells were tested for the presence of opioid receptors. [3H]Diprenorphine binds to NMB cell membranes with a KD value of 0.46 +/- 0.13 nM and Bmax of 534 +/- 22 fmol/mg protein. The presence of mu, delta, and kappa opioid receptors was tested by displacing [3H]diprenorphine specific binding by the selective agonists DAMGO, DPDPE, and U50,488H, respectively. Using this procedure, the data suggest that the NMB neuroblastoma cells express the three opioid receptor types with the abundance of delta receptors (about 60%) and minor, yet substantial populations of mu and kappa receptors (about 20% each).
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PMID:Evidence for mu-, delta-, and kappa-opioid receptors in a human neuroblastoma cell line. 838 37

The site of interaction of opioids and inhalation anaesthetic agents is unknown, but may be at the level of the opioid receptor. In this study we have used SH-SY5Y human neuroblastoma cells, which express both mu and delta receptors, to examine the effects of halothane on the receptor binding profiles of [3H]diprenorphine (DPN), an opioid receptor antagonist, and [3H] [D-Ala2,MePhe4, Gly(ol)5]enkephalin (DAMGO), a mu receptor selective agonist. Binding of [3H]DPN and [3H]DAMGO was performed at 37 degrees C for 60 min in the presence of air, nitrous oxide (75%) or air containing halothane (0.5-5.0% v/v). Compared with air controls, neither 75% nitrous oxide nor 0.5, 1.0, 2.0 and 5.0% halothane influenced DPN binding variables. Binding of [3H]DAMGO was unaffected by 1.0% halothane, but 5.0% halothane reduced the affinity, with a modest increase in Kd (1.15 (0.16) to 1.7 (0.2) nmol litre-1) without effect on Bmax. Our data suggest that the site of opioid and volatile anaesthetic interaction is not at the opioid receptor.
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PMID:Do nitrous oxide and halothane influence opioid receptor binding in SH-SY5Y human neuroblastoma cells? 867 25

1. In this study we have investigated delta and mu opioid receptor-mediated elevation of intracellular Ca2+ concentration ([Ca2+]i) in the human neuroblastoma cell line, SH-SY5Y. 2. The Ca(2+)-sensitive dye, fura-2, was used to measure [Ca2+]i in confluent monolayers of SH-SY5Y cells. Neither the delta-opioid agonist, DPDPE ([D-Pen2,5]-enkephalin) nor the mu-opioid agonist, DAMGO (Tyr-D-Ala-Gly-N-Me-Phe-Gly-ol enkephalin) elevated [Ca2+]i when applied alone. However, when either DPDPE or DAMGO was applied in the presence of the cholinoceptor agonist, carbachol (100 nM-1 mM) they evoked an elevation of [Ca2+]i above that caused by carbachol alone. 3. In the presence of 1 microM or 100 microM carbachol, DPDPE elevated [Ca2+]i with an EC50 of 10 nM. The elevation of [Ca2+]i was independent of the concentration of carbachol. The EC50 for DAMGO elevating [Ca2+]i in the presence of 1 microM and 100 microM carbachol was 270 nM and 145 nM respectively. 4. The delta-receptor antagonist, naltrindole (30 nM), blocked the elevations of [Ca2+]i by DPDPE (100 nM) without affecting those caused by DAMGO while the mu-receptor antagonist, CTAP (D-Phe-Cys-Tyr-D-Trp-Arg-Pen-Thr-NH2) (100 nM-1 microM) blocked the elevations of [Ca2+]i caused by DAMGO (1 microM) without affecting those caused by DPDPE. 5. Block of carbachol activation of muscarinic receptors with atropine (10 microM) abolished the elevation of [Ca2+]i by the opioids. The nicotinic receptor antagonist, mecamylamine (10 microM), did not affect the elevations of [Ca2+]i caused by opioids in the presence of carbachol. 6. Muscarinic receptor activation, not a rise in [Ca2+]i, was required to reveal the opioid response. The Ca2+ channel activator, maitotoxin (3 ng ml-1), also elevated [Ca2+]i but subsequent application of opioid in the presence of maitotoxin caused no further changes in [Ca2+]i. 7. The elevations of [Ca2+]i by DPDPE and DAMGO were abolished by pretreatment of the cells with pertussis toxin (200 ng ml-1, 16 h). This treatment did not significantly affect the response of the cells to carbachol. 8. The opioids appeared to elevate [Ca2+]i by mobilizing Ca2+ from intracellular stores. Both DPDPE and DAMGO continued to elevate [Ca2+]i when applied in nominally Ca(2+)-free external buffer or when applied in a buffer containing a cocktail of Ca2+ entry inhibitors. Thapsigargin (100 nM), an agent which discharges intracellular Ca2+ stores, also blocked the opioid elevations of [Ca2+]i. 9. delta and mu Opioids did not appear to mobilize intracellular Ca2+ by modulating the activity of protein kinases. The application of H-89 (10 microM), an inhibitor of protein kinase A, H-7 (100 microM), an inhibitor of protein kinase C, protein kinase A and cyclic GMP-dependent protein kinase, or Bis I, an inhibitor of protein kinase C, did not alter the opioid mobilization of [Ca2+]i. 10. Thus, in SH-SY5Y cells, opioids can mobilize Ca2+ from intracellular stores but they require ongoing muscarinic receptor activation. Opioids do not elevate [Ca2+]i when applied alone.
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PMID:delta- and mu-opioid receptor mobilization of intracellular calcium in SH-SY5Y human neuroblastoma cells. 878 87


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