1. CB2 expression in mouse brain: from mapping to regulation in microglia under inflammatory conditions.
- Author
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Grabon, Wanda, Ruiz, Anne, Gasmi, Nadia, Degletagne, Cyril, Georges, Béatrice, Belmeguenai, Amor, Bodennec, Jacques, Rheims, Sylvain, Marcy, Guillaume, and Bezin, Laurent
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CANNABINOID receptors , *BRAIN mapping , *GENETIC transcription , *MICROGLIA , *INFLAMMATION - Abstract
Since its detection in the brain, the cannabinoid receptor type 2 (CB2) has been considered a promising therapeutic target for various neurological and psychiatric disorders. However, precise brain mapping of its expression is still lacking. Using magnetic cell sorting, calibrated RT-qPCR and single-nucleus RNAseq, we show that CB2 is expressed at a low level in all brain regions studied, mainly by few microglial cells, and by neurons in an even lower proportion. Upon lipopolysaccharide stimulation, modeling neuroinflammation in non-sterile conditions, we demonstrate that the inflammatory response is associated with a transient reduction in CB2 mRNA levels in brain tissue, particularly in microglial cells. This result, confirmed in the BV2 microglial cell line, contrasts with the positive correlation observed between CB2 mRNA levels and the inflammatory response upon stimulation by interferon-gamma, modeling neuroinflammation in sterile condition. Discrete brain CB2 expression might thus be up- or down-regulated depending on the inflammatory context. Highlights : Tissue level of CB2 receptor mRNA is low and uniform across the various brain regions examined. The use of transcription and translation inhibitors during brain dissociation and cell sorting is efficient to prevent microglia ex vivo activation. CB2 mRNA was detected in scarce cells at the physiological state, was mainly detected in microglia and in some neurons. CB2 expression is downregulated in microglia during LPS-induced inflammatory peak and upregulated during the resolution of inflammation. LPS and IFNγ stimulation differently regulate CB2 expression in microglia. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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