Co-Expression of Human Somatostatin Receptor Subtypes 2 and 3 in HEK-293 Cells Modulates Antiproliferative Signaling and Apoptosis

We have evaluated 3 newly developed neuropeptide Y receptor antagonists in various in vitro binding and bioassays: BIBO3304 (Y1), T4[NPY33-36]4 (Y2), and CGP71683A (Y5). In rat brain homogenates, BIBO3304 competes for the same population of [125I][Leu31,Pro34] peptide YY (PYY) binding sites (75%) as BIBP3226, but with a 10 fold greater affinity (IC50 of 0.2 ± 0.04 nM for BIBO3304 vs. 2.4 ± 0.07 nM for BIBP3226),while CGP71683A has high affinity for 25% of specific [125I][Leu31,Pro34]PYY binding sites. Both BIBO3304 and CGP71683A (at 1.0 µM) were unable to compete for a significant proportion of specific [125I]PYY3-36/Y2 sites. The purported Y2 antagonist T4[NPY33-36]4 competed against [125I]PYY3-36 binding sites with an affinity of 750 nM. These results were confirmed in HEK 293 cells transfected with either the rat Y1, Y2, Y4, or Y5 receptor cDNA. BIBO3304, but not CGP71683A, competed with high affinity for [125I][Leu31,Pro34]PYY binding sites in HEK 293 cells transfected with the rat Y1 receptor cDNA, whereas the reverse profile was observed upon transfection with the rat Y5 receptor cDNA. Additionally, both molecules were inactive at Y2 and Y4 receptor subtypes expressed in HEK 293 cells. Receptor autoradiographic studies revealed the presence of [125I][Leu31,Pro34]PYY/BIBO3304-insensitive sites in the rat brain as reported previously for BIBP3226. Finally, the selective antagonistic properties of BIBO3304 were demonstrated in a Y1 bioassay (rabbit saphenous vein; pA2 value of 9.04) while being inactive in Y2 (rat vas deferens) and Y4 (rat colon) bioassays. These results confirm the high affinity and selectivity of BIBO3304 and CGP71683A for the Y1 and Y5 receptor subtypes, respectively, while the purported Y2 antagonist, T4[NPY33-36]4 possesses rather low affinity for this receptor.Key words: NPY receptor antagonist, receptor subtypes, bioassays, receptor binding assays, autoradiographic studies, receptor distribution.

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Pharmacology of the agonist binding sites of rat neuronal nicotinic receptor subtypes expressed in HEK 293 cells

Bioorganic & Medicinal Chemistry Letters ◽

10.1016/j.bmcl.2003.09.105 ◽

2004 ◽

Vol 14 (8) ◽

pp. 1845-1848 ◽

Cited By ~ 28

Author(s):

Yingxian Xiao ◽

Maryna Baydyuk ◽

Haizhu (Pearl) Wang ◽

Heather E Davis ◽

Kenneth J Kellar

Keyword(s):

Binding Sites ◽

Nicotinic Receptor ◽

Receptor Subtypes ◽

Agonist Binding ◽

Hek 293 ◽

Neuronal Nicotinic Receptor ◽

Hek 293 Cells ◽

293 Cells ◽

Nicotinic Receptor Subtypes

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Evidence for the existence of P2Y1,2,4 receptor subtypes in HEK-293 cells: reactivation of P2Y1 receptors after repetitive agonist application

Naunyn-Schmiedeberg s Archives of Pharmacology ◽

10.1007/s00210-005-1070-6 ◽

2005 ◽

Vol 371 (6) ◽

pp. 466-472 ◽

Cited By ~ 25

Author(s):

Wolfgang Fischer ◽

Heike Franke ◽

Helke Gröger-Arndt ◽

Peter Illes

Keyword(s):

Receptor Subtypes ◽

Hek 293 ◽

Hek 293 Cells ◽

293 Cells

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Characterization of 17-β-Estradiol-dependent and -independent Somatostatin Receptor Subtypes in Rat Anterior Pituitary

Journal of Biological Chemistry ◽

10.1016/s0021-9258(18)83536-0 ◽

1989 ◽

Vol 264 (12) ◽

pp. 7033-7040

Author(s):

N Kimura ◽

C Hayafuji ◽

N Kimura

Keyword(s):

Anterior Pituitary ◽

Somatostatin Receptor ◽

Receptor Subtypes ◽

Somatostatin Receptor Subtypes

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Characteristics and requirements of basal autophagy in HEK 293 cells

Autophagy ◽

10.4161/auto.25455 ◽

2013 ◽

Vol 9 (9) ◽

pp. 1407-1417 ◽

Cited By ~ 41

Author(s):

Patience Musiwaro ◽

Matthew Smith ◽

Maria Manifava ◽

Simon A. Walker ◽

Nicholas T. Ktistakis

Keyword(s):

Hek 293 ◽

Hek 293 Cells ◽

293 Cells

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Halothane Inhibition of Recombinant Cardiac L-type Ca2+ Channels Expressed in HEK-293 Cells

Anesthesiology ◽

10.1097/00000542-200512000-00009 ◽

2005 ◽

Vol 103 (6) ◽

pp. 1156-1166 ◽

Cited By ~ 7

Author(s):

Kevin J. Gingrich ◽

Son Tran ◽

Igor M. Nikonorov ◽

Thomas J. Blanck

Keyword(s):

Charge Transfer ◽

Calcium Channels ◽

Dependent Manner ◽

Current Time ◽

Hek 293 ◽

Hek 293 Cells ◽

293 Cells ◽

Dependent Inactivation ◽

Voltage Dependent

Background Volatile anesthetics depress cardiac contractility, which involves inhibition of cardiac L-type calcium channels. To explore the role of voltage-dependent inactivation, the authors analyzed halothane effects on recombinant cardiac L-type calcium channels (alpha1Cbeta2a and alpha1Cbeta2aalpha2/delta1), which differ by the alpha2/delta1 subunit and consequently voltage-dependent inactivation. Methods HEK-293 cells were transiently cotransfected with complementary DNAs encoding alpha1C tagged with green fluorescent protein and beta2a, with and without alpha2/delta1. Halothane effects on macroscopic barium currents were recorded using patch clamp methodology from cells expressing alpha1Cbeta2a and alpha1Cbeta2aalpha2/delta1 as identified by fluorescence microscopy. Results Halothane inhibited peak current (I(peak)) and enhanced apparent inactivation (reported by end pulse current amplitude of 300-ms depolarizations [I300]) in a concentration-dependent manner in both channel types. alpha2/delta1 coexpression shifted relations leftward as reported by the 50% inhibitory concentration of I(peak) and I300/I(peak)for alpha1Cbeta2a (1.8 and 14.5 mm, respectively) and alpha1Cbeta2aalpha2/delta1 (0.74 and 1.36 mm, respectively). Halothane reduced transmembrane charge transfer primarily through I(peak) depression and not by enhancement of macroscopic inactivation for both channels. Conclusions The results indicate that phenotypic features arising from alpha2/delta1 coexpression play a key role in halothane inhibition of cardiac L-type calcium channels. These features included marked effects on I(peak) inhibition, which is the principal determinant of charge transfer reductions. I(peak) depression arises primarily from transitions to nonactivatable states at resting membrane potentials. The findings point to the importance of halothane interactions with states present at resting membrane potential and discount the role of inactivation apparent in current time courses in determining transmembrane charge transfer.

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