Voltage‐Sensitive Calcium Channels in Differentiated Neuroblastoma × Glioma Hybrid (NG108–15) Cells: Characterization by Quin 2 Fluorescence

Noronha-Blob, Lalita; Richard, C A; U’Prichard, David C.

doi:10.1111/j.1471-4159.1988.tb03020.x

Cited by 45 publications

(18 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To evaluate whether voltagegated Ca 2ϩ channels might represent an additional route for Ca 2ϩ -mediated regulation of PDE1A in 1321N1 cells, we looked for Ca 2ϩ influx in the presence of depolarizing concentrations of KCl (20 -60 mM). Not even the highest concentration of KCl could trigger Ca 2ϩ entry (data not shown), which concurs with the reported absence of voltage-gated Ca 2ϩ entry channels in 1321N1 cells (43,44). Therefore, this issue cannot be resolved with this model system.…”

Section: Cch Mediates a Casupporting

confidence: 82%

Sustained Entry of Ca2+ Is Required to Activate Ca2+-Calmodulin-dependent Phosphodiesterase 1A

Goraya

Masada

Ciruela

et al. 2004

Journal of Biological Chemistry

View full text Add to dashboard Cite

Regulation of adenylyl cyclases (ACs) byA rise in [Ca 2ϩ ] i 1 leads to an inhibition of cAMP accumulation in a variety of cell types (1-8). In some cases, the inhibition of cAMP accumulation is exerted on Ca 2ϩ -inhibitable adenylyl cyclases (ACs) (1-3, 5-7), whereas in others the effect may be mediated by Ca 2ϩ -calmodulin-dependent phosphodiesterases (PDE1) (4, 8). ACs are extremely discriminating in terms of the source of the Ca 2ϩ to which they respond (9). In non-excitable cells, Ca 2ϩ -sensitive ACs respond only to CCE (9), whereas other modes of elevating [Ca 2ϩ ] i , including release from intracellular stores (6, 7, 10) and ionophore-(6, 7, 10) or arachidonic acid-mediated Ca 2ϩ entry (11), are ineffective. This dependence, along with other evidence, suggests that Ca 2ϩ -sensitive ACs and CCE channels must be functionally co-localized and that cellular strategies are in place to ensure their association (12, 13). By contrast, although type I PDEs (PDE1) are known to be markedly stimulated by Ca 2ϩ acting via calmodulin in vitro, little if anything is known about the mode of [Ca 2ϩ ] i rise to which they will respond in the intact cell.In the human astrocytoma cell line 1321N1, the activation of receptors that stimulate the formation of inositol 1,4,5-trisphosphate (InsP 3 ) substantially inhibits cAMP accumulation (8,14,15). Complete reversal of the inhibition by PDE1-specific inhibitors is consonant with the agonist-evoked rise in [Ca 2ϩ ] i -activating PDE1 and hence increasing the rate of cAMP hydrolysis (16). Indeed, these early studies established that PDE1 activity is markedly increased when Ca 2ϩ is introduced into the extracellular medium (14, 15). Therefore, PDE1 does seem to be regulated by [Ca 2ϩ ] i , but the source of the Ca 2ϩ to which PDE1 responds and whether PDE1 is as discriminating as Ca 2ϩ -sensitive ACs has never been addressed. In the present study, we first characterized the various modes by which [Ca 2ϩ ] i could be elevated in 1321N1 cells. We then established a variety of conditions to manipulate [Ca 2ϩ ] i so that we could ask whether PDE1 discriminates between Ca 2ϩ signaling pathways, viz. Ca 2ϩ released from intracellular stores, and the different modes of Ca 2ϩ entry. We also established by RT-PCR that PDE1A was the only PDE1 isoform expressed in these cells. Furthermore, we compared the effect of Ca 2ϩ entry following stimulation with the muscarinic agonist carbachol (CCh) or non-selective entry mediated by the ionophore, ionomycin, and the triggering of CCE by the sarco-(endo)plasmic reticulum Ca 2ϩ -ATPase inhibitor, thapsigargin, on isoproterenol-evoked cAMP accumulation. Our findings establish that Ca 2ϩ entry is the major stimulus for PDE1A in 1321N1 cells, but unlike Ca 2ϩ -sensitive ACs, PDE1A does not discriminate between different modes of Ca 2ϩ entry. We wondered whether the lack of selectivity for the source of Ca 2ϩ entry was related to the subcellular distribution of PDE1A. Following fractionation of the cells, we found that Ca 2ϩ -calmodulin-s...

show abstract

Section: Cch Mediates a Casupporting

confidence: 82%

Sustained Entry of Ca2+ Is Required to Activate Ca2+-Calmodulin-dependent Phosphodiesterase 1A

Goraya

Masada

Ciruela

et al. 2004

Journal of Biological Chemistry

View full text Add to dashboard Cite

show abstract

“…We observed that the Ca agonists Bay, YC and CGP have little enhancing effect on basal 45Ca uptake by Bt2 cAMP-treated and untreated NG108-15 cells under non depolarizing conditions (5 mM KC1, data not shown), as observed previously (6,7,9). Our observations suggest that the enhancing effect on KCI-stimulated 45Ca uptake in differentiated NG108-15 cells was voltage-dependent.…”

supporting

confidence: 70%

“…Therefore, the present report describes the systematic study of the enhancing effects of these Ca agonists. Our results for Bay and CGP were more similar to those of Noronha-Blob et al (7) than to those of Freedman and Miller (6), since Noronha-Blob et al (7) observed that Bay is more potent than CGP in terms of enhancement rate and ED50 value for 45Ca up take. These differing reports may be a function of the differing reaction times adopted for the 45Ca uptake.…”

supporting

confidence: 67%

“…We concluded that the enhancement of KC1-stimulat ed 45Ca uptake by differentiated NG108-15 cells with Bt2cAMP is due, at least in part, to an increase in the amount of specific [3H](+)PN200-110 (PN) binding sites; i.e., the cells showed a quantitative increase in peripheral L-type voltage-sensitive Ca channels (VSCCs) (5). It was also ob served that the Ca-channel agonist (Ca agonist) Bay K 8644 (Bay) enhanced KCl-stimulated 45Ca uptake in differentiated NG108-15 cells (4,6,7). However, there has been little investigation regarding the enhancing effects of various Ca agonists on KC1-stimulated 45Ca uptake by differentiated (treated with Bt2cAMP) and undifferentiat ed (without Bt2cAMP treatment) NG108-15 cells.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Effects of Ca Channel Agonists on 45Ca Uptake Differ Depending on the State of NG108-15 Cells

Ichida

Wada

Matsuda

et al. 1994

Japanese Journal of Pharmacology

View full text Add to dashboard Cite

ABSTRACT-We investigated the effects of various Ca channel agonists (Ca agonist) derived from 1,4-dihy dropyridine on KC1-stimulated 45Ca uptake by differentiated and undifferentiated neuroblastoma x glioma hybrid NG108-15 cells with and without dibutyryl cAMP. Ca agonists Bay K 8644, YC-170 and CGP 28392 enhanced KCl-stimulated 45Ca uptake in differentiated NG108-15 cells, but only slightly in undifferentiated NG108-15 cells. The rank order of the enhancing effects was roughly Bay K 8644 > YC-170 > CGP 28392. These results suggest that there is some difference between the mechanisms by which these Ca agonists affect KCl-stimulated 45Ca uptake in differentiated and undifferentiated NG108-15 cells, although the nature of that difference is not clear.

show abstract

“…[5][6][7][8][9][10] Voltage-sensitive sodium channels (VSSCs) have been existed not only in neuron, cardiac and skeletal muscle, but also in a variety of hormone secretory cells. VSSCs play a critical role in controlling the electrical excitability of animal cells, being primarily responsible for the rising phase of the action potential.…”

mentioning

confidence: 99%

Enhancement of Veratridine-Induced Sodium Dynamics in NG108-15 Cells during Differentiation

Imanishi

Matsushima

Kawaguchi

et al. 2006

Biological & Pharmaceutical Bulletin

View full text Add to dashboard Cite

An NG108-15 cell line, a hybrid cell line, is artificially formed by the fusion of mouse neuroblastoma (N18TG-2) and rat glioma (C6-Bu1) cell lines. NG108-15 cells have been used as a suitable model system to investigate the mechanisms of neuronal development and differentiation. 1)When NG108-15 cells are differentiated in culture with inducing reagents such as dibutyryl cAMP (Bt 2 cAMP), prostaglandin E 1 (PG E 1 ) plus theophylline, forskolin, dexamethasone, retinoic acid etc., the cells exhibit the growth of neurites characteristic of neuronal differentiation. 2)We have reported that the rate of KCl-stimulated 45 Ca uptake in differentiated NG108-15 cells (treated with Bt 2 cAMP) was significantly higher than that in undifferentiated cells and that the 45 Ca uptake was selectively inhibited by various blockers of L-type voltage-sensitive Ca 2ϩ channels (VSCCs).3) The B max value for specific binding of (ϩ ] i ) induced by high-KCl application and the amplitude of Ca 2ϩ current were significantly augmented when NG108-15 cells were differentiated. 5-10)Voltage-sensitive sodium channels (VSSCs) have been existed not only in neuron, cardiac and skeletal muscle, but also in a variety of hormone secretory cells. VSSCs play a critical role in controlling the electrical excitability of animal cells, being primarily responsible for the rising phase of the action potential. 11,12) In mammalian nerve and muscle cells, VSSCs consist of a pore-forming a subunit in association with one or two auxiliary b subunits. a Subunits have been cloned nine isoforms (Na V 1.1-1.9). These isoforms have been classified as members of a single gene family, Na V 1, on the basis of amino acid sequences. Six isoforms (Na V 1.1-1.4, 1.6 and 1.7) are all considered 'tetrodetoxin (TTX)-sensitive' Na ϩ channels. On the other hand, the remaining three isoforms (Na V 1.5, 1.8 and 1.9) are all considered 'TTX-resistant' Na ϩ channels. In addition, b subunits have been identified three isoforms (b1-b3).In contrast, little is known about developmental changes in the dynamics of Na ϩ during differentiation of NG108-15 cells. The present work, therefore, aims to reveal any developmental alterations in intracellular Na ϩ concentration ([Na ϩ ] i ) evoked by the application of high-KCl solution or veratridine (Vtd), a VSSCs agonist. It is to be noted that voltage-sensitive Na ϩ channels (VSSCs) are characteristic of mammalian nerve cells, 11,12) and NG108-15 cells are thought to obtain neuronal features when differentiated. 1) MATERIALS AND METHODSCell Culture NG108-15 cells (passage number: less than 15) were grown in high glucose Dulbecco's modified Eagle's medium (DMEM) containing 10% fetal bovine serum and 0.1 mM hypoxanthine, 1 mM aminopterin, 16 mM thymidine (HAT) under a humidified atmosphere of 7.5% CO 2 at 37°C. The cells were harvested and subcultured by reseeding at a density of about 10 4 cells/ml, in culture dishes with quartz bottoms, which were precoated with poly-L-ornithine. On the following day, 0.75 mM Bt 2 cAMP was added to the...

show abstract

Voltage‐Sensitive Calcium Channels in Differentiated Neuroblastoma × Glioma Hybrid (NG108–15) Cells: Characterization by Quin 2 Fluorescence

Cited by 45 publications

References 43 publications

Sustained Entry of Ca2+ Is Required to Activate Ca2+-Calmodulin-dependent Phosphodiesterase 1A

Sustained Entry of Ca2+ Is Required to Activate Ca2+-Calmodulin-dependent Phosphodiesterase 1A

Effects of Ca Channel Agonists on 45Ca Uptake Differ Depending on the State of NG108-15 Cells

Enhancement of Veratridine-Induced Sodium Dynamics in NG108-15 Cells during Differentiation

Contact Info

Product

Resources

About