Skip to main content

Impact of the endocannabinoid system on murine cranial and alveolar bone phenotype.

Annals of anatomy = Anatomischer Anzeiger : official organ of the Anatomische Gesellschaft

Authors: Maria Setiawan, Andreas Jäger, Nikolaos Daratsianos, Susanne Reimann, Junliang Chen, Anne-Caroline Schmöle, Daniel Derichs-Schönthal, Anna Konermann

PURPOSE: The endocannabionoid signaling system has been demonstrated to be present in the skeleton, with involvement in the regulation of skeletal homeostasis. However, investigations substantiating these findings in cranial and alveolar bones are missing to date. The aim of our study was to investigate a potential impact of the endocannabinoid system on cranial and alveolar bone structures and phenotypes.

BASIC PROCEDURES: CB1, CB2 and WT mice (n = 5) were scanned via μCT. Reconstructed datasets were processed for analyses. Cranial cephalometric measurements were performed with OnyxCephsoftware. Alveolar bone densities were determined via mean grey value measurements with Mimics research 18.0. Alveolar bone heights around teeth in upper and lower jaws were morphometrically analyzed. Alveolar osteoclasts were quantified via TRAP staining of paraffin-embedded histologies. Bone-marrow derived macrophages isolated from murine hind legs were analyzed for CD40 and MMR expression via flow cytometry.

MAIN FINDINGS: CB2 mice exhibited significantly higher bone densities with mean grey values of 138.3 ± 22.6 compared to 121.9 ± 9.3 for WT for upper jaws, and 134.6 ± 22.9 compared to 116.1 ± 12.9 for WT 134.6 ± 22.9. Concurrently, CB2 receptor knockout entailed reduced alveolar bone heights of about 50% compared to WT mice. Antigen-presenting cell marker expression of MMR was significantly diminished in bone-marrow derived macrophages of CB2 mice. Cranium dimensions as much as alveolar osteoclasts were unaffected by receptor knockouts.CB1 receptor knockout did not involve statistically significant alterations in the parameters investigated compared to WT mice.

PRINCIPAL CONCLUSIONS: The endoncannabinoid system, and particularly CB2 receptor strongly affects murine alveolar bone phenotypes. These observations suggest CB2 as promising target in the modulation of oral bone phenotypes, probably by impact on bone dynamics via osteal immune cells.

Copyright © 2020 Elsevier GmbH. All rights reserved.

PMID: 32240731

Participating cluster members