The resolvin D1 receptor GPR32 transduces inflammation resolution and atheroprotection
Hildur Arnardottir, … , Göran K. Hansson, Magnus Bäck
Hildur Arnardottir, … , Göran K. Hansson, Magnus Bäck
Published October 26, 2021
Citation Information: J Clin Invest. 2021;131(24):e142883. https://doi.org/10.1172/JCI142883.
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Research Article Cardiology Inflammation Article has an altmetric score of 239

The resolvin D1 receptor GPR32 transduces inflammation resolution and atheroprotection

Abstract

Chronic inflammation is a hallmark of atherosclerosis and results from an imbalance between proinflammatory and proresolving signaling. The human GPR32 receptor, together with the ALX/FPR2 receptor, transduces biological actions of several proresolving mediators that stimulate resolution of inflammation. However, since no murine homologs of the human GPR32 receptor exist, comprehensive in vivo studies are lacking. Using human atherosclerotic lesions from carotid endarterectomies and creating a transgenic mouse model expressing human GPR32 on a Fpr2×ApoE double-KO background (hGPR32myc×Fpr2–/–×Apoe–/–), we investigated the role of GPR32 in atherosclerosis and self-limiting acute inflammation. GPR32 mRNA was reduced in human atherosclerotic lesions and correlated with the immune cell markers ARG1, NOS2, and FOXP3. Atherosclerotic lesions, necrotic core, and aortic inflammation were reduced in hGPR32mycTg×Fpr2–/–×Apoe–/– transgenic mice as compared with Fpr2–/–×Apoe–/– nontransgenic littermates. In a zymosan-induced peritonitis model, the hGPR32mycTg×Fpr2–/–×Apoe–/– transgenic mice had reduced inflammation at 4 hours and enhanced proresolving macrophage responses at 24 hours compared with nontransgenic littermates. The GPR32 agonist aspirin-triggered resolvin D1 (AT-RvD1) regulated leukocyte responses, including enhancing macrophage phagocytosis and intracellular signaling in hGPR32mycTg×Fpr2–/–×Apoe–/– transgenic mice, but not in Fpr2–/–×Apoe–/– nontransgenic littermates. Together, these results provide evidence that GPR32 regulates resolution of inflammation and is atheroprotective in vivo.

Authors

Hildur Arnardottir, Silke Thul, Sven-Christian Pawelzik, Glykeria Karadimou, Gonzalo Artiach, Alessandro L. Gallina, Victoria Mysdotter, Miguel Carracedo, Laura Tarnawski, April S. Caravaca, Roland Baumgartner, Daniel F.J. Ketelhuth, Peder S. Olofsson, Gabrielle Paulsson-Berne, Göran K. Hansson, Magnus Bäck

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Figure 5

AT-RvD1 alters leukocyte responses and regulates phosphorylation of ERK1/2 in hGPR32mycTg×Fpr2–/–×Apoe–/– but not Fpr2–/–×Apoe–/– mice.

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AT-RvD1 alters leukocyte responses and regulates phosphorylation of ERK1...
Naive resident peritoneal macrophages were isolated and seeded in a 96-well plate (0.1 × 106 cells/well). Uptake of pH-rodo labeled (A) zymosan (n = 6) or (B) E. coli (n = 10) by peritoneal macrophages from Fpr2–/–×Apoe–/– (open boxes) and hGPR32mycTg×Fpr2–/–×Apoe–/– (filled boxes) that were pretreated with vehicle (black outline) or AT-RvD1 (100 nM, 15 minutes, 37°C; blue outline) followed by 60 minutes of incubation with the phagocytic stimuli. Results are expressed as relative fluorescence units (RFU). (C) Peritoneal macrophages were preincubated with AT-RvD1 (100 nM, 15 minutes, 37°C) followed by the addition of FITC-labeled oxLDL (10 μg/ml) to assess phagocytosis of oxLDL. Images were recorded every 1 hour for a total of 24 hours. Data are presented as percentages of maximum phagocytosis (after 24 hours). Results are expressed as mean ± SEM. Changes in (D) pERK and (E) pCREB activation in peritoneal macrophages treated with AT-RvD1 (10 or 100 nM; 5 minutes, 37°C) from vehicle control in Fpr2–/–×Apoe–/– (open box, n = 4) and hGPR32mycTg×Fpr2–/–×Apoe–/– (filled box, n = 6) mice. Results are expressed as median with minimum to maximum bars. *P < 0.05; **P < 0.01; ****P < 0.0001 vs. vehicle-treated hGPR32mycTg×Fpr2–/–×Apoe–/– macrophages. #P < 0.05; ##P < 0.01; ####P < 0.0001 in AT-RvD1–treated Fpr2–/–×Apoe–/– vs. AT-RvD1–treated hGPR32mycTg×Fpr2–/–×Apoe–/– macrophages; 2-way ANOVA.