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G protein-coupled receptor 21 in macrophages: An in vitro study
Valentina Bordano1, Gemma K Kinsella2, Stefania Cannito3
1Dipartimento di Scienza e Tecnologia del Farmaco, University of Turin, Turin, Italy.
European Journal of Pharmacology
|May 10, 2022
Summary
Pharmacological inhibition of G protein-coupled receptor 21 (GPR21) impacts macrophage function. This study found that inhibiting GPR21 reduces pro-inflammatory cytokine release and differentially affects macrophage migration, suggesting therapeutic potential for chronic inflammation.
Area of Science:
- Immunology
- Pharmacology
- Cell Biology
Background:
- G protein-coupled receptor 21 (GPR21) is an orphan receptor expressed in macrophages.
- Previous studies in mice suggest GPR21 influences macrophage migration.
Purpose of the Study:
- To investigate the role of GPR21 in human macrophages, focusing on cell migration and cytokine release.
- To evaluate the effects of the GPR21 inverse agonist, GRA2, on macrophage functions.
Main Methods:
- THP-1 cells were differentiated into M1 or M2 macrophages.
- GPR21 expression, signaling, and cytokine release (TNF-α, IL-1β) were analyzed.
- Cell migration assays were performed on macrophages treated with GRA2 or GPR21 siRNA.
Main Results:
- GRA2 significantly reduced TNF-α and IL-1β release from M1 macrophages.
- GRA2 inhibited M1 macrophage migration but promoted M2 macrophage migration.
- GRA2 was confirmed to act as a GPR21 inverse agonist.
Conclusions:
- GPR21 plays a role in human macrophage migration and cytokine release.
- Pharmacological inhibition of GPR21 with GRA2 modulates these functions.
- Targeting GPR21 may offer a therapeutic strategy for chronic inflammatory conditions.
