TY - JOUR
T1 - Multipathway In Vitro Pharmacological Characterization of Specialized Proresolving G Protein-Coupled Receptors
AU - Merlin, Jon
AU - Park, Julia
AU - Vandekolk, Teresa H.
AU - Fabb, Stewart A.
AU - Allinne, Jeanne
AU - Summers, Roger J.
AU - Langmead, Christopher J.
AU - Riddy, Darren M.
N1 - Funding Information:
This work received no external funding but was partially funded by Servier Laboratories. No author has an actual or perceived conflict of interest with the contents of this article. 1J.M. and J.P. contributed equally to this work. dx.doi.org/10.1124/molpharm.121.000422. SThis article has supplemental material available at molpharm. aspetjournals.org.
Publisher Copyright:
© 2022 by The American Society.
PY - 2022/4/1
Y1 - 2022/4/1
N2 - Specialized proresolving mediators (SPMs) and their cognate G protein-coupled receptors are implicated in autoimmune disorders, including chronic inflammation, rheumatoid arthritis, systemic scleroderma, and lupus erythematosus. To date, six G protein-coupled receptors (GPCRs) have been paired with numerous endogenous and synthetic ligands. However, the function and downstream signaling of these receptors remains unclear. To address this knowledge gap, we systematically expressed each receptor in a human embryonic kindney 293 (HEK293)-Flp-In- CD8a-FLAG cell system. Each receptor was pharmacologically characterized with both synthetic and putative endogenous ligands across different signaling assays, covering both G proteindependent (Gs, Gi, and Gq) and independent mechanisms (b-arrestin2 recruitment). Three orphan GPCRs previously identified as SPM receptors (GPR 18, GPR32 and GPR37) failed to express in HEK 293 cells. Although we were unsuccessful in identifying an endogenous ligand for formyl peptide receptor 2 (FPR2)/lipoxin A4 receptor (ALX), with only a modest response to N-formylmethionine-leucyl-phenylalanine (fMLP), we did reveal clear signaling bias away from extracelluar signal-related kinase (ERK) 1/2 phosphorylation for the clinically tested agonist N-(2-f[4-(1,1-difluoroethyl)- 1,3-oxazol-2-yl]methylg-2H-1,2,3-triazol-4-yl)-2-methyl-5-(3-methylphenyl)-1,3-oxazole-4-carboxamide (ACT-389949), adding further evidence for its poor efficacy in two phase I studies.We also identified neuroprotectin D1 as a new leukotriene B4 receptor 1 (BLT1) agonist, implying an alternative target for the neuroprotective effects of the ligand. We confirmed activity for resolvin E1 (RvE1) at BLT1 but failed to observe any response at the chemerin1 receptor. This study provides some much-needed clarity around published receptor-ligand pairings but indicates that the expression and function of these SPM GPCRs remains very much context-dependent. In addition, the identification of signaling bias at FPR2/ALX may assist in guiding design of new FPR2/ALX agonists for the treatment of autoimmune disorders.
AB - Specialized proresolving mediators (SPMs) and their cognate G protein-coupled receptors are implicated in autoimmune disorders, including chronic inflammation, rheumatoid arthritis, systemic scleroderma, and lupus erythematosus. To date, six G protein-coupled receptors (GPCRs) have been paired with numerous endogenous and synthetic ligands. However, the function and downstream signaling of these receptors remains unclear. To address this knowledge gap, we systematically expressed each receptor in a human embryonic kindney 293 (HEK293)-Flp-In- CD8a-FLAG cell system. Each receptor was pharmacologically characterized with both synthetic and putative endogenous ligands across different signaling assays, covering both G proteindependent (Gs, Gi, and Gq) and independent mechanisms (b-arrestin2 recruitment). Three orphan GPCRs previously identified as SPM receptors (GPR 18, GPR32 and GPR37) failed to express in HEK 293 cells. Although we were unsuccessful in identifying an endogenous ligand for formyl peptide receptor 2 (FPR2)/lipoxin A4 receptor (ALX), with only a modest response to N-formylmethionine-leucyl-phenylalanine (fMLP), we did reveal clear signaling bias away from extracelluar signal-related kinase (ERK) 1/2 phosphorylation for the clinically tested agonist N-(2-f[4-(1,1-difluoroethyl)- 1,3-oxazol-2-yl]methylg-2H-1,2,3-triazol-4-yl)-2-methyl-5-(3-methylphenyl)-1,3-oxazole-4-carboxamide (ACT-389949), adding further evidence for its poor efficacy in two phase I studies.We also identified neuroprotectin D1 as a new leukotriene B4 receptor 1 (BLT1) agonist, implying an alternative target for the neuroprotective effects of the ligand. We confirmed activity for resolvin E1 (RvE1) at BLT1 but failed to observe any response at the chemerin1 receptor. This study provides some much-needed clarity around published receptor-ligand pairings but indicates that the expression and function of these SPM GPCRs remains very much context-dependent. In addition, the identification of signaling bias at FPR2/ALX may assist in guiding design of new FPR2/ALX agonists for the treatment of autoimmune disorders.
UR - http://www.scopus.com/inward/record.url?scp=85127099620&partnerID=8YFLogxK
U2 - 10.1124/molpharm.121.000422
DO - 10.1124/molpharm.121.000422
M3 - Article
C2 - 35125345
AN - SCOPUS:85127099620
SN - 1521-0111
VL - 101
SP - 246
EP - 256
JO - Molecular Pharmacology
JF - Molecular Pharmacology
IS - 4
ER -