Impact of species variability and "probe-dependence" on the detection and in vivo validation of allosteric modulation at the M(4) muscarinic acetylcholine receptor

Nur Suraya Suratman, Katherine Leach, Patrick Sexton, Christian C Felder, Richard Loiacono, Arthur Christopoulos

Research output: Contribution to journalArticleResearchpeer-review

Abstract

Background and Purpose We recently characterized LY2033298 as a novel allosteric modulator and agonist at M(4) mAChRs. Evidence also suggested a difference in the potency of LY2033298 at rodent relative to human M(4) mAChRs. The current study investigated the basis for the species difference of this modulator and used this knowledge to rationalise its in vivo actions. Experimental Approach LY2033298 was investigated in vitro in CHO cells stably expressing human or mouse M(4) mAChRs, using assays of agonist-induced ERK1/2 or GSK3alpha phosphorylation, [(35) S]-GTPgammaS binding, or effects on equilibrium binding of [(3) H]-NMS and ACh. The in vivo actions of LY2033298 were investigated in a mouse model of amphetamine-induced locomotor activity. The function of LY2033298 was examined in combination with ACh, oxotremorine or xanomeline. Key Results LY2033298 had similar affinities for the human and mouse M(4) mAChRs. However, LY2033298 had a lower positive co-operativity with ACh at the mouse relative to the human M(4) mAChR. At the mouse M(4) mAChR, LY2033298 showed higher cooperativity with oxotremorine than with ACh or xanomeline. The different degrees of cooperativity between LY2033298 and each agonist at the mouse relative to the human M(4) mAChR necessitated the co-administration of LY2033298 with oxotremorine in order to show in vivo efficacy of LY2033298. Conclusions and Implications These results provide evidence for species variability when comparing the allosteric interaction between LY2033298 and ACh at the M(4) mAChR, and also highlight how the interaction between LY2033298 and different orthosteric ligands is subject to probe dependence . This has implications for the validation of allosteric modulator actions in vivo.
Original languageEnglish
Pages (from-to)1659 - 1670
Number of pages12
JournalBritish Journal of Pharmacology
Volume162
Issue number7
DOIs
Publication statusPublished - 2011

Cite this

@article{08de902512b94195a3832aacfb2f83ee,
title = "Impact of species variability and {"}probe-dependence{"} on the detection and in vivo validation of allosteric modulation at the M(4) muscarinic acetylcholine receptor",
abstract = "Background and Purpose We recently characterized LY2033298 as a novel allosteric modulator and agonist at M(4) mAChRs. Evidence also suggested a difference in the potency of LY2033298 at rodent relative to human M(4) mAChRs. The current study investigated the basis for the species difference of this modulator and used this knowledge to rationalise its in vivo actions. Experimental Approach LY2033298 was investigated in vitro in CHO cells stably expressing human or mouse M(4) mAChRs, using assays of agonist-induced ERK1/2 or GSK3alpha phosphorylation, [(35) S]-GTPgammaS binding, or effects on equilibrium binding of [(3) H]-NMS and ACh. The in vivo actions of LY2033298 were investigated in a mouse model of amphetamine-induced locomotor activity. The function of LY2033298 was examined in combination with ACh, oxotremorine or xanomeline. Key Results LY2033298 had similar affinities for the human and mouse M(4) mAChRs. However, LY2033298 had a lower positive co-operativity with ACh at the mouse relative to the human M(4) mAChR. At the mouse M(4) mAChR, LY2033298 showed higher cooperativity with oxotremorine than with ACh or xanomeline. The different degrees of cooperativity between LY2033298 and each agonist at the mouse relative to the human M(4) mAChR necessitated the co-administration of LY2033298 with oxotremorine in order to show in vivo efficacy of LY2033298. Conclusions and Implications These results provide evidence for species variability when comparing the allosteric interaction between LY2033298 and ACh at the M(4) mAChR, and also highlight how the interaction between LY2033298 and different orthosteric ligands is subject to probe dependence . This has implications for the validation of allosteric modulator actions in vivo.",
author = "Suratman, {Nur Suraya} and Katherine Leach and Patrick Sexton and Felder, {Christian C} and Richard Loiacono and Arthur Christopoulos",
year = "2011",
doi = "10.1111/j.1476-5381.2010.01184.x",
language = "English",
volume = "162",
pages = "1659 -- 1670",
journal = "British Journal of Pharmacology",
issn = "1476-5381",
publisher = "Wiley-Blackwell",
number = "7",

}

TY - JOUR

T1 - Impact of species variability and "probe-dependence" on the detection and in vivo validation of allosteric modulation at the M(4) muscarinic acetylcholine receptor

AU - Suratman, Nur Suraya

AU - Leach, Katherine

AU - Sexton, Patrick

AU - Felder, Christian C

AU - Loiacono, Richard

AU - Christopoulos, Arthur

PY - 2011

Y1 - 2011

N2 - Background and Purpose We recently characterized LY2033298 as a novel allosteric modulator and agonist at M(4) mAChRs. Evidence also suggested a difference in the potency of LY2033298 at rodent relative to human M(4) mAChRs. The current study investigated the basis for the species difference of this modulator and used this knowledge to rationalise its in vivo actions. Experimental Approach LY2033298 was investigated in vitro in CHO cells stably expressing human or mouse M(4) mAChRs, using assays of agonist-induced ERK1/2 or GSK3alpha phosphorylation, [(35) S]-GTPgammaS binding, or effects on equilibrium binding of [(3) H]-NMS and ACh. The in vivo actions of LY2033298 were investigated in a mouse model of amphetamine-induced locomotor activity. The function of LY2033298 was examined in combination with ACh, oxotremorine or xanomeline. Key Results LY2033298 had similar affinities for the human and mouse M(4) mAChRs. However, LY2033298 had a lower positive co-operativity with ACh at the mouse relative to the human M(4) mAChR. At the mouse M(4) mAChR, LY2033298 showed higher cooperativity with oxotremorine than with ACh or xanomeline. The different degrees of cooperativity between LY2033298 and each agonist at the mouse relative to the human M(4) mAChR necessitated the co-administration of LY2033298 with oxotremorine in order to show in vivo efficacy of LY2033298. Conclusions and Implications These results provide evidence for species variability when comparing the allosteric interaction between LY2033298 and ACh at the M(4) mAChR, and also highlight how the interaction between LY2033298 and different orthosteric ligands is subject to probe dependence . This has implications for the validation of allosteric modulator actions in vivo.

AB - Background and Purpose We recently characterized LY2033298 as a novel allosteric modulator and agonist at M(4) mAChRs. Evidence also suggested a difference in the potency of LY2033298 at rodent relative to human M(4) mAChRs. The current study investigated the basis for the species difference of this modulator and used this knowledge to rationalise its in vivo actions. Experimental Approach LY2033298 was investigated in vitro in CHO cells stably expressing human or mouse M(4) mAChRs, using assays of agonist-induced ERK1/2 or GSK3alpha phosphorylation, [(35) S]-GTPgammaS binding, or effects on equilibrium binding of [(3) H]-NMS and ACh. The in vivo actions of LY2033298 were investigated in a mouse model of amphetamine-induced locomotor activity. The function of LY2033298 was examined in combination with ACh, oxotremorine or xanomeline. Key Results LY2033298 had similar affinities for the human and mouse M(4) mAChRs. However, LY2033298 had a lower positive co-operativity with ACh at the mouse relative to the human M(4) mAChR. At the mouse M(4) mAChR, LY2033298 showed higher cooperativity with oxotremorine than with ACh or xanomeline. The different degrees of cooperativity between LY2033298 and each agonist at the mouse relative to the human M(4) mAChR necessitated the co-administration of LY2033298 with oxotremorine in order to show in vivo efficacy of LY2033298. Conclusions and Implications These results provide evidence for species variability when comparing the allosteric interaction between LY2033298 and ACh at the M(4) mAChR, and also highlight how the interaction between LY2033298 and different orthosteric ligands is subject to probe dependence . This has implications for the validation of allosteric modulator actions in vivo.

UR - http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=21198541

U2 - 10.1111/j.1476-5381.2010.01184.x

DO - 10.1111/j.1476-5381.2010.01184.x

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VL - 162

SP - 1659

EP - 1670

JO - British Journal of Pharmacology

JF - British Journal of Pharmacology

SN - 1476-5381

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