In:
British Journal of Pharmacology, Wiley, Vol. 163, No. 2 ( 2011-05), p. 313-329
Abstract:
Despite growing evidence that inhibition of α6β2‐containing (α6β2*) nicotinic acetylcholine receptors (nAChRs) may be beneficial for the therapy of tobacco addiction, the lack of good sources of α6β2*‐nAChRs has delayed the discovery of α6β2‐selective antagonists. Our aim was to generate a cell line stably expressing functional nAChRs with α6β2 properties, to enable pharmacological characterization and the identification of novel α6β2‐selective antagonists. EXPERIMENTAL APPROACH Different combinations of the α6, β2, β3, chimeric α6/3 and mutant β3 V273S subunits were transfected in human embryonic kidney cells and tested for activity in a fluorescent imaging plate reader assay. The pharmacology of rat immune‐immobilized α6β2*‐nAChRs was determined with 125 I‐epibatidine binding. KEY RESULTS Functional channels were detected after co‐transfection of α6/3, β2 and β3 V273S subunits, while all other subunit combinations failed to produce agonist‐induced responses. Stably expressed α6/3β2β3 V273S ‐nAChR pharmacology was unique, and clearly distinct from α4β2‐, α3β4‐, α7‐ and α1β1δε‐nAChRs. Antagonist potencies in inhibiting α6/3β2β3 V273S ‐nAChRs was similar to their binding affinity for rat native α6β2*‐nAChRs. Agonist affinities for α6β2*‐nAChRs was higher than their potency in activating α6/3β2β3 V273S ‐nAChRs, but their relative activities were equivalent. Focussed set screening at α6/3β2β3 V273S ‐nAChRs, followed by cross‐screening with the other nAChRs, led to the identification of novel α6β2‐selective antagonists. CONCLUSIONS AND IMPLICATIONS We generated a mammalian cell line stably expressing nAChRs, with pharmacological properties similar to native α6β2*‐nAChRs, and used it to identify novel non‐peptide, low molecular weight, α6β2‐selective antagonists. We also propose a pharmacophore model of α6β2 antagonists, which offers a starting point for the development of new smoking cessation agents.
Type of Medium:
Online Resource
ISSN:
0007-1188
,
1476-5381
DOI:
10.1111/bph.2011.163.issue-2
DOI:
10.1111/j.1476-5381.2011.01213.x
Language:
English
Publisher:
Wiley
Publication Date:
2011
detail.hit.zdb_id:
2029728-2
SSG:
15,3
