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Query: UMLS:C0027819 (neuroblastoma)
 27,800 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To define mechanisms by which inflammatory cells damage neural tissue, the author investigated stimuli that promote leukocyte adherence and injury to cultured human cortical neuron (HCN-1) and neuroblastoma cells (LAN-1 and SK-N-SH). Neutrophils do not adhere to unstimulated neural cells but will bind to neural cells that have been exposed to tumor necrosis factor alpha (TNF alpha) and in some cases other cytokines such as gamma interferon (gamma IFN) or interleukin-1 (IL-1). Tumor necrosis factor alpha induces synthesis of intercellular adhesion molecule-1 (ICAM-1) mRNA and cell surface expression of ICAM-1 on cultured neural cells. Adherence of neutrophils to cytokine-stimulated neural cells is mediated primarily by ICAM-1:LFA-1 interactions, because 70% to 90% of the binding can be blocked by monoclonal antibodies to either ligand. Prior introduction of an oxidizable dye, 5-(and 6-)carboxy-2',7' dichlorofluorescin diacetate into the LAN-1 cells demonstrates that adherent neutrophils can release oxidizing radicals into the neural cell cytoplasm. These results suggest that cytokines released in the course of inflammation may induce expression of ICAM-1 on neurons, allowing them to be targeted by leukocytes expressing the appropriate receptors. The resulting adhesive interactions may facilitate introduction of various toxic agents into the neural cytoplasm.
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PMID:Induction of ICAM-1 on human neural cells and mechanisms of neutrophil-mediated injury. 168 66

Single smooth muscle cells were isolated from the basilar artery of the rat by enzymatic dispersion. The membrane properties of the cells were assessed using the patch-electrode voltage-clamp technique, and cell viability was monitored using fluorescein diacetate uptake. Exposure of the cells to oxyhemoglobin (5 microM) resulted in 1) contraction, 2) the appearance of membrane blebs, 3) an increase in the outward potassium currents, 4) a decrease in the membrane resistance, and 5) cell death. In contrast, no effect of oxyhemoglobin on cultured murine neuroblastoma cells was observed. Methemoglobin (100 microM) had no effects on the smooth muscle cells. Catalase (300 units/ml) or dimethyl sulfoxide (0.5%) protected against the effects of oxyhemoglobin; superoxide dismutase (100-1,000 units/ml) provided only partial protection. Exposure of the cells to superoxide anions generated by xanthine (1 mM) plus xanthine oxidase (10 units/l) or to hydrogen peroxide (500 microM) caused an increase in the outward potassium currents without affecting membrane resistance. Generation of hydroxyl radicals by metal ions plus hydrogen peroxide caused the same effects as oxyhemoglobin, that is, an increase in the potassium currents, followed by a decrease in the membrane resistance and cell death. In conclusion, it appears that oxyhemoglobin exerts its effects on vascular smooth muscle cells by the generation of free radicals, chiefly hydroxyl radicals.
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PMID:Free radicals mediate actions of oxyhemoglobin on cerebrovascular smooth muscle cells. 199 46

1. Activation of protein kinase C (PKC) by phorbol esters or diacylglycerols has been shown to modulate a number of ionic currents carried by Ca2+, K+ and Cl-. Recently, it has been demonstrated that PKC may be activated by cis-fatty acids in the absence of either phospholipid or Ca2+. We wished to determine if this new class of PKC-activating compound would also modulate ionic currents. To this end we applied the whole-cell voltage-clamp technique to N1E-115 neuroblastoma cells. 2. Analysis of families of currents evoked under voltage clamp by depolarizing steps from a holding potential of -85 mV during external application of 5 microM-oleate (a cis-fatty acid) showed a 36% reduction of the peak inward current with no shift in either the peak or the reversal potential of the current-voltage relation and no alteration of outward current. 3. External application of the cis-fatty acids oleate, linoleate and linolenate reversibly attenuated voltage-dependent Na+ current with approximate half-maximal dose values of 2, 3, and 10 microM respectively. Oleate was approximately 2 times more potent when applied internally (ED50 = 1 microM). Externally applied elaidate (a trans-isomer of oleate) and stearate (a saturated fatty acid) which do not activate PKC, had no effect. Since cis-fatty acids are known to fluidize membranes, as well as to activate PKC, we sought to dissociate these functions by applying compounds that fluidize membranes but do not activate PKC: methyloleate and lysophosphatidylcholine. Neither compound affected Na+ current when applied externally at concentrations of 1-50 microM. 4. In contrast to cis-fatty acids, three classical PKC activators, phorbol-12.13-dibutyrate (PDB), phorbol-12.13-diacetate (PDA), and 1.2-oleoylacetylglycerol (OAG) were found to have no effect on the voltage-dependent Na+ current when applied externally at 10 nM-1 microM (phorbol esters) or 1-150 microM (OAG) for incubation periods up to 1 h. 5. External application of the PKC inhibitors polymyxin B, H-7, sphingosine and staurosporine blocked the attenuation of the Na+ current by cis-fatty acid in a dose-dependent manner, with maximal inhibition occurring at doses of 50, 10, 200 and 0.1 microM, respectively. The cyclic nucleotide-dependent protein kinase inhibitor H-8 was much less effective in blocking the cis-fatty acid effect. Polymyxin B and staurosporine were more potent when applied internally. 6. Chronic (24 h) exposure to 1 microM phorbol-12-myristate-13-acetate (TPA) was employed to down-regulate PKC.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:cis-Fatty acids, which activate protein kinase C, attenuate Na+ and Ca2+ currents in mouse neuroblastoma cells. 255 78

It is important to apply an appropriate test for determining cell viability, in order to properly evaluate the role of the amyloid beta protein in neuronal degeneration in Alzheimer's disease. In the current paper, we present evidence that the putative neurotoxic fragment 25-35 of amyloid beta causes loss of trypan blue exclusion in differentiated mouse neuroblastoma N1E-115 cells which suggests a potential neurotoxic effect. Surprisingly, no parallel changes in apparent cell viability were observed when fluorescein diacetate staining or release of lactate dehydrogenase were measured. Positive staining with trypan blue was also induced by incubating cell membranes prepared from N1E-115 cells or rat hippocampus with amyloid beta 25-35. Our results indicate that amyloid beta might induce trypan blue adsorption on the cell membrane. Therefore, caution should be taken when trypan blue exclusion is used in studies of the potential neurotoxicity of amyloid beta peptides.
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PMID:An artifact associated with using trypan blue exclusion to measure effects of amyloid beta on neuron viability. 808 5

Patients with amyotrophic lateral sclerosis possess antibodies (ALS IgGs) that bind to L-type skeletal muscle voltage-gated calcium channels (VGCCs) and inhibit L-type calcium current. To determine whether interaction of ALS IgGs with neuronal VGCCs might influence motoneuron survival, we used a motoneuron-neuroblastoma hybrid (VSC 4.1) cell line expressing binding sites for inhibitors of L-, N-, and P-type VGCCs. Using direct viable cell counts, quantitation of propidium iodide- and fluorescein diacetate-labeled cells, and lactate dehydrogenase release to assess cell survival, we document that ALS IgG kills 40-70% of cAMP-differentiated VSC 4.1 cells within 2 days. ALS IgG-mediated cytotoxicity is dependent on extracellular calcium and is prevented by peptide antagonists of N- or P-type VGCCs but not by dihydropyridine modulators of L-type VGCCs. Preincubating IgG with purified intact L-type VGCC or with isolated VGCC alpha 1 subunit also blocks ALS IgG-mediated cytotoxicity. These results suggest that ALS IgG may directly lead to motoneuron cell death by a mechanism requiring extracellular calcium and mediated by neuronal-type calcium channels.
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PMID:Cytotoxicity of immunoglobulins from amyotrophic lateral sclerosis patients on a hybrid motoneuron cell line. 815 58

Adding the membrane-permeant oxidant tert-butylhydroperoxide (t-BOOH) to the incubation medium, in SH-SY5Y human neuroblastoma cells, induced a marked and progressive concentration-dependent (300, 500 and 1000 microM) increase of free radical production, as evaluated by the fluorescent probe 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA) and of the intracellular Ca(2+) ion concentrations [Ca(2+)](i). The removal of extracellular Ca(2+) ions did not prevent t-BOOH-induced [Ca(2+)](i) elevation, whereas the intracellular Ca(2+) ion chelator 1,2-bis(o-aminophenoxy) ethane-N,N, N',N'-tetraacetic acid (BAPTA) (10 microM) was shown to be effective. Both t-BOOH-induced free radical formation and the [Ca(2+)](i) increase were completely prevented by the peroxyl scavenger alpha-tocopherol (50 microM). t-BOOH induced a time-dependent SH-SY5Y cell injury, monitored by a 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay (approximately 25% at 1 h, 50% at 3 h, 80% at 5 h) and by fluorescein diacetate (FDA)-propidium iodide (PI) fluorescent staining. The entity of t-BOOH-induced cell damage was the same both in the absence and in the presence of the intracellular Ca(2+) ion chelator BAPTA. By contrast, the peroxyl scavenger alpha-tocopherol (50 microM) completely prevented cell injury due to oxidative stress. Finally, superoxide dismutase (SOD) (500 ng/ml) caused a 30% reduction of t-BOOH-induced 2', 7'-dichlorofluorescein (DCF) fluorescence, whereas it did not modify the extent of cell injury produced by the oxidant. Collectively, the results of the present study demonstrated that in SH-SY5Y human neuroblastoma cells, the rise of [Ca(2+)](i) which occurs during oxidative stress is not involved in cell injury. Therefore, oxidative stress-induced cell death may be exclusively attributed to free radical overproduction.
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PMID:In the neuronal cell line SH-SY5Y, oxidative stress-induced free radical overproduction causes cell death without any participation of intracellular Ca(2+) increase. 1055 68

Neutrophils and mononuclear cells (MNC) can mediate antibody-dependent cellular cytotoxicity (ADCC) against cancer cells. To study cytotoxicity and growth inhibition of neuroblastoma cells by neutrophils and MNC with chimeric anti-disialoganglioside (GD2) monoclonal antibody (mAb) ch14.18, we developed digital image microscopy scanning (DIMSCAN) assays that measure fluorescence of target cells in 96-well plates after 6-18 h (cytotoxicity assay) or 7 days (growth assay). Neuroblastoma cell lines (GD2-positive: SMS-KCN, SMS-LHN, LA-N-1; GD2-negative: SK-N-SH) were preloaded with calcein acetoxymethyl ester for the cytotoxicity assay or labeled in situ after 7 days of culture with fluorescein diacetate in the growth assay. Fluorescence, as quantified by DIMSCAN, was correlated with neuroblastoma cell number in both assays (100-2000 cells/well). In the cytotoxicity test, both neutrophils and MNC effectively mediated ADCC of GD2-positive but not GD2-negative neuroblastoma cell lines. Cytotoxicity of both neutrophils and MNC increased with effector to target cell (E:T) ratio (5-50:1) and mAb ch.14.18 dose (0.1-10 microg/ml). ADCC of neutrophils, but not MNC, increased with addition of GM-CSF. Neutrophils, especially with rhGM-CSF, significantly suppressed growth of GD2-positive cell lines at a high E:T ratio (50:1) and mAb dose (10 microg/ml). Without antibody, neutrophils inhibited growth of one cell line (LA-N-1) but stimulated growth of two others (SMS-KCN, SMS-LHN). If neuroblastoma cells did not express GD2 (SK-N-SH), neutrophils stimulated growth whether or not antibody was present. Neutrophil culture supernatants increased growth of SK-N-SH, LA-N-1, and SMS-KCN cells, and MNC culture supernatants increased growth of SK-N-SH. In conclusion, neutrophils can mediate cytotoxicity and growth inhibition with a chimeric anti-GD2 antibody but also can promote tumor cell growth if antibody is not present or if GD2 is not expressed.
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PMID:Neutrophils are cytotoxic and growth-inhibiting for neuroblastoma cells with an anti-GD2 antibody but, without cytotoxicity, can be growth-stimulating. 1066 7

The possible use of neuropeptide Y (NPY) as a novel radiopeptide has been investigated. NPY is a 36-amino acid peptide of the pancreatic polypeptide family, which is expressed in the peripheral and central nervous system, and is one of the most abundant neuropeptides in the brain. Its receptors are produced in a number of neuroblastoma and the thereof derived cell lines. As structure-activity relationships of NPY are well-known, we could assume where a radionuclide might be introduced without affecting receptor affinity. We applied the novel [99mTc(OH2)3(CO)3]+ aqua complex and PADA (2-picolylamine-N,N-diacetic acid) as bifunctional chelating agent. The peptides were synthesized by solid-phase peptide synthesis, and PADA was coupled to the side chain of Lys4 of the resin-bound peptide. Upon postlabeling of [K4(PADA)]-NPY, 99mTc(CO)3 did not only bind to the desired PADA, but presumably as well to the His in position 26. Since the replacement of His26 by Ala only slightly decreased binding affinity, [K4(PADA),A26]-NPY was specifically postlabeled, and the 185Re surrogate maintained high binding affinity. Furthermore, the prelabeling approach has been applied for the centrally truncated analogue [Ahx5-24]-NPY, which is highly selective for the Y2 receptor. The resulting Ac-[Ahx5-24,K4(99mTc(CO)3-PADA)]-NPY was produced with a yield of only 16%. Therefore, postlabeling was applied for the short analogue as well, again substituting His26 by Ala. Competitive binding assays using (185)Re as a surrogate for 99mTc showed high binding affinity of Ac-[Ahx5-24,K4(185Re(CO)3-PADA),A26]-NPY. Internalization studies with the corresponding 99mTc-labeled analogue revealed receptor-mediated internalization. Furthermore, biodistribution studies were performed in mice, and stability was tested in human plasma. Our centrally truncated analogue revealed a 6-fold increased stability compared to the natural peptide NPY. We conclude that Ac-[Ahx5-24,K4(99mTc(CO)3-PADA),A26]-NPY has promising characteristics for future applications in nuclear medicine.
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PMID:99mTc-labeled neuropeptide Y analogues as potential tumor imaging agents. 1171 96

The mitogen-activated protein kinase (MAP kinase) pathway participates in a number of reactions of the cell when responding to various external stimuli. These stimuli include growth factor binding to its receptor as well as stressful situations such as hypoxia and oxidative stress. It has been postulated that one of the mechanisms by which beta-amyloid exerts its toxic effects is to produce oxidative stress. This study therefore investigated whether the MAP-kinase pathway was activated in cells following exposure to beta-amyloid. Neuroblastoma (N2alpha) cells were used in all experiments. The cells were exposed to 50, 100, and 500 microM glutamate, and 10, 30, and 50 microM beta-amyloid, for 24 h. The methylthiazolyl tetrazolium salt (MTT) assay was performed to determine the degree of toxicity. The generation of hydrogen peroxide was detected by fluorescence microscopy using the dye dihydrochlorofluorescein diacetate (DCDHF). Extracellular-signal-regulated kinase (ERK) and p38 MAP-kinase phosphorylation, as representatives of the MAP-kinase pathway, was determined. Treating N2alpha cells with beta-amyloid resulted in a greater than 50% reduction in cell viability. These cells also showed a significantly higher presence of hydrogen peroxide. Western Blot analysis revealed that the phosphorylation of p38 MAP kinase was dose-dependently increased in cells exposed to glutamate and beta-amyloid. On the other hand, the phosphorylation of ERK was significantly reduced in these cells. These data therefore suggest that the toxic effects of beta-amyloid involve the generation of hydrogen peroxide, leading to the activation of p38 and the down-regulation of ERK.
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PMID:The role of the MAP-kinase superfamily in beta-amyloid toxicity. 1176 30

The current work tested the hypothesis that the zinc status of a cell influences its sensitivity to iron-induced oxidative stress. Human IMR-32 neuroblastoma cells were cultured for 24 h in nonchelated control media (5 microM zinc; 4.5 microM iron), or in media that was treated with DTPA to reduce its zinc content (chelated media). Chelated media was supplemented with zinc to achieve concentrations of 1.5-50 microM Zn. The media was then replaced with serum-free complex media (0.9 microM Zn) with either no added iron (0.6 microM Fe), or iron (FeCl(3)) added at concentrations ranging from 15 to 100 microM. Cells were cultured for an additional 3- to 24-hour period. Over the 24-hour period, cells cultured in the control iron media had good viability, and they displayed the gross morphology typical of these cells in culture. With 100 microM iron, cell viability was low in all groups. After 24 h and at iron concentrations between 15-50 microM, cells that had been cultured in the low zinc-chelated media (1.5 microM Zn) showed a concentration-dependent increase in 5 (or 6)-carboxy-2'7'-dichlorodihydrofluorescein diacetate (DCDCDHF) fluorescence (oxidative stress) and decrease in cell viability. A positive correlation between both parameters was observed (r = 0.92). These cells had altered morphology and high level of nucleosomes suggestive of cell death by apoptosis. These results support the concept that the zinc status of IMR-32 neuroblastoma cells modulates their sensitivity to iron overload.
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PMID:Zinc status of human IMR-32 neuroblastoma cells influences their susceptibility to iron-induced oxidative stress. 1240 50


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