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Pharmacology of α7 nicotinic acetylcholine receptor mediated extracellular signal‐regulated kinase signalling in PC12 cells
Author(s) -
Kouhen R El,
Hu M,
Anderson DJ,
Li J,
Gopalakrishnan M
Publication year - 2009
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1111/j.1476-5381.2008.00069.x
Subject(s) - nicotinic agonist , extracellular , pharmacology , acetylcholine , signal transduction , nicotinic acetylcholine receptor , acetylcholine receptor , microbiology and biotechnology , signalling , chemistry , kinase , muscarinic acetylcholine receptor m5 , receptor , muscarinic acetylcholine receptor m3 , neuroscience , biology , biochemistry
Background and purpose: Neuronal nicotinic acetylcholine receptors (nAChR) can modulate cell survival and memory processing. The involvement of specific nAChR subtypes in downstream signalling events has been ill defined thus far, because of a lack of subtype‐selective ligands. In this study, we investigated activation and modulation of α7 nAChR‐mediated phosphorylation of extracellular signal‐regulated kinases (ERK1/2) in PC12 cells, using selective agonists and positive allosteric modulators. Experimental approach: We used undifferentiated PC12 cells endogenously expressing α7 nAChR for both biochemical and functional studies. ERK phosphorylation changes were measured by using a novel In‐Cell Western procedure. α7 nAChR‐mediated Ca 2+ signalling was determined by using the fluorometric imaging plate reader assay. Key results: Robust induction of ERK phosphorylation followed exposure of PC12 cells to the selective agonist PNU‐282987 in the presence of the α7 nAChR modulator PNU‐120596. ERK phosphorylation was transient and was attenuated by the selective antagonist methyllycaconitine. Consistent with allosteric modulation of α7 nAChRs, PNU‐120596 enhanced both the agonist potency and efficacy in activating ERK. Moreover, α7 nAChR agonists could be quantitatively differentiated based on their potency in activating ERK signalling. The rank order of potencies correlated fairly well with the corresponding binding K i values of these α7 nAChR agonists. Conclusions and implications: The present work extends previous observations demonstrating the involvement of α7 nAChRs in ERK1/2 phosphorylation in PC12 cells. The In‐Cell Western procedure allowed a detailed investigation of α7 nAChR function and downstream ERK signalling in response to agonist and allosteric modulators. Mandarin translation of abstract