Journal Article

Ackr3-Venus knock-in mouse lights up brain vasculature

Couvineau, Pierre, Le Gouill, Christian, Darcq, Emmanuel, Bouvier, Michel, Gross, Florence, Thelen, Marcus, Semache, Meriem, Kieffer, Brigitte L., Kobayashi, Hiroyuki, Hogue, Mireille, Wojcik, Stefan, Ehrlich, Aliza T.

2021

Overview

The atypical chemokine receptor 3, ACKR3, is a G protein-coupled receptor, which does not couple to G proteins but recruits βarrestins. At present, ACKR3 is considered a target for cancer and cardiovascular disorders, but less is known about the potential of ACKR3 as a target for brain disease. Further, mouse lines have been created to identify cells expressing the receptor, but there is no tool to visualize and study the receptor itself under physiological conditions. Here, we engineered a knock-in (KI) mouse expressing a functional ACKR3-Venus fusion protein to directly detect the receptor, particularly in the adult brain. In HEK-293 cells, native and fused receptors showed similar membrane expression, ligand induced trafficking and signaling profiles, indicating that the Venus fusion does not alter receptor signaling. We also found that ACKR3-Venus enables direct real-time monitoring of receptor trafficking using resonance energy transfer. In ACKR3-Venus knock-in mice, we found normal ACKR3 mRNA levels in the brain, suggesting intact gene transcription. We fully mapped receptor expression across 14 peripheral organs and 112 brain areas and found that ACKR3 is primarily localized to the vasculature in these tissues. In the periphery, receptor distribution aligns with previous reports. In the brain there is notable ACKR3 expression in endothelial vascular cells, hippocampal GABAergic interneurons and neuroblast neighboring cells. In conclusion, we have generated Ackr3-Venus knock-in mice with a traceable ACKR3 receptor, which will be a useful tool to the research community for interrogations about ACKR3 biology and related diseases.

• Publisher: BioMed Central,BioMed Central Ltd,Springer Nature B.V,BMC
• Subject: Animals / B cells / Bacterial Proteins - analysis / Bacterial Proteins - genetics / Bacterial Proteins - pharmacokinetics / beta-Arrestin 1 - metabolism / Biomarkers / Biomedical and Life Sciences / Biomedicine / Biosensors / Brain / Brain - blood supply / Cancer / Chemokine receptors / Chemokines / Computer Systems / CXCR7 / Endothelial Cells - chemistry / Endothelial Cells - cytology / Energy transfer / Fusion protein / G protein / G proteins / GABA / GABAergic Neurons - chemistry / GABAergic Neurons - cytology / Gene expression / Gene Knock-In Techniques / Genes, Reporter / Genetic transcription / GPCR / HEK293 Cells / Hippocampus / Humans / Interneurons / Interneurons - chemistry / Interneurons - cytology / Kinases / Life Sciences / Ligands / Localization / Luminescent Proteins - analysis / Luminescent Proteins - genetics / Luminescent Proteins - pharmacokinetics / Membrane proteins / Membrane trafficking / Mice / Neurology / Neurons and Cognition / Neurosciences / Organ Specificity / Phosphorylation / Physiological aspects / Physiology / Protein transport / Proteins / Psychopharmacology / Receptors, CXCR - analysis / Receptors, CXCR - genetics / Recombinant Proteins - analysis / Recombinant Proteins - genetics / Recombinant Proteins - pharmacokinetics / Signaling / Tissue Distribution / Transcription / βarrestin / γ-Aminobutyric acid