Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The . gov means it’s official. Federal government websites often end in VSports app下载. gov or . mil. Before sharing sensitive information, make sure you’re on a federal government site. .

Https

The site is secure. The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely V体育官网. .

. 2009 Sep 22;106(38):16511-6.
doi: 10.1073/pnas.0902743106. Epub 2009 Sep 3.

The putative cannabinoid receptor GPR55 affects osteoclast function in vitro and bone mass in vivo (VSports最新版本)

Lauren S Whyte  1 , Erik Ryberg, Natalie A Sims, Susan A Ridge, Ken Mackie, Peter J Greasley, Ruth A Ross, Michael J Rogers
Affiliations

The putative cannabinoid receptor GPR55 affects osteoclast function in vitro and bone mass in vivo

"VSports" Lauren S Whyte et al. Proc Natl Acad Sci U S A. .

Abstract

GPR55 is a G protein-coupled receptor recently shown to be activated by certain cannabinoids and by lysophosphatidylinositol (LPI). However, the physiological role of GPR55 remains unknown. Given the recent finding that the cannabinoid receptors CB(1) and CB(2) affect bone metabolism, we examined the role of GPR55 in bone biology. GPR55 was expressed in human and mouse osteoclasts and osteoblasts; expression was higher in human osteoclasts than in macrophage progenitors. Although the GPR55 agonists O-1602 and LPI inhibited mouse osteoclast formation in vitro, these ligands stimulated mouse and human osteoclast polarization and resorption in vitro and caused activation of Rho and ERK1/2. These stimulatory effects on osteoclast function were attenuated in osteoclasts generated from GPR55(-/-) macrophages and by the GPR55 antagonist cannabidiol (CBD) VSports手机版. Furthermore, treatment of mice with this non-psychoactive constituent of cannabis significantly reduced bone resorption in vivo. Consistent with the ability of GPR55 to suppress osteoclast formation but stimulate osteoclast function, histomorphometric and microcomputed tomographic analysis of the long bones from male GPR55(-/-) mice revealed increased numbers of morphologically inactive osteoclasts but a significant increase in the volume and thickness of trabecular bone and the presence of unresorbed cartilage. These data reveal a role of GPR55 in bone physiology by regulating osteoclast number and function. In addition, this study also brings to light an effect of both the endogenous ligand, LPI, on osteoclasts and of the cannabis constituent, CBD, on osteoclasts and bone turnover in vivo. .

PubMed Disclaimer

V体育平台登录 - Conflict of interest statement

Conflict of interest statement: E. R. and P. J. G. are employees of AstraZeneca V体育安卓版.

Figures

Fig. 1.
Fig. 1.
Effect of GPR55 ligands on human and mouse osteoclast formation. (A) Human monocytes were cultured in the presence of 1 nM to 1 μM CBD for 7 days and then were fixed and stained for αvβ3 (vitronectin receptor, VNR) to quantify osteoclast number. Immunofluorescence intensity was measured and expressed relative to control cultures. Data are mean ± SEM; n = 6 or 7 independent experiments, with 5 replicates for each. ANOVA with Dunnett's post-test; **, P < 0.01; ***, P < 0.001 compared with control. (B and C) BMMs from wild-type mice (black bar) and GPR55−/− mice (white bar) were cultured in the presence of 5 nM to 1 μM O-1602 (B) or 1 nM to 1 μM LPI (C) for 5 days and then were fixed and stained for TRAP. The number of TRAP-positive multinucleated cells (MNCs) was counted and expressed as a percentage of control. Data are mean ± SEM; n = 4 or 5 experiments, 5 replicates for each. ANOVA with Bonferroni post-test; *, P < 0.05; ***, P < 0.001 compared with control; #, P < 0.05; ##, P < 0.01; ###, P < 0.001 compared with wild type. (D) Representative images of TRAP-positive MNCs (arrowheads) generated from wild-type and GPR55−/− macrophages after treatment with vehicle (control) or 100 nM O-1602. (Scale bar: 50 μm.)
Fig. 2.
Fig. 2.
O-1602 and LPI stimulate human osteoclast polarization and resorption. Human osteoclasts cultured on dentine discs were treated with vehicle (control) or 1 nM to 1 μM O-1602 with or without 500 nM CBD for 5 days. (A) The number of F-actin rings is expressed as percentage of control cultures ± SEM. Black bars represent O-1602 alone (n = 5 experiments with 5 replicates for each); white bars represent O-1602 + 500 nM CBD (n = 4 experiments with 4 or 5 replicates for each). ANOVA with Bonferroni post-test; *, P < 0.05; **, P < 0.01 compared with control; #, P < 0.05; ###, P < 0.001 compared with O-1602 alone. (B) Resorption area is expressed as percentage of control ± SEM. Black bars represent O-1602 alone (n = 5 experiments with 5 replicates for each); white bars represent O-1602 + 500 nM CBD (n = 4 experiments with 4 or 5 replicates for each). ANOVA with Bonferroni post-test; *, P < 0.05 compared with control; ###, P < 0.001 compared with O-1602 alone. (C) Representative images of human osteoclasts cultured on dentine, after treatment with vehicle (control), 50 nM O-1602, or 50 nM O-1602 + 500 nM CBD. Cells were stained to visualize polarized cells with F-actin rings (Inset). (D) Human osteoclasts on dentine discs were treated with vehicle (control) or 1 nM to 1 μM LPI for 5 days. The number of F-actin rings is expressed as percentage of control cultures ± SEM (n = 4 experiments with 4 or 5 replicates for each). ANOVA with Dunnett's post-test; *, P < 0.05; **, P < 0.01 compared with control. (E) Resorption area is expressed as percentage of control ± SEM. (n = 4 experiments with 3–5 replicates for each). ANOVA with Dunnett's post-test; **, P < 0.01.
Fig. 3.
Fig. 3.
O-1602 and LPI stimulate Rho activation and ERK phosphorylation in human and mouse osteoclasts. (A) Human osteoclasts were treated with O-1602 (O), LPI, or CBD for 10 min, with or without a 10-min pre-incubation with 1 μM CBD. Activation of Rho and ERK1/2 was measured on Western blots by densitometry; values are means ± SEM from 3–7 independent experiments. **, P < 0.01; ***, P < 0.001 compared with control (Ctrl); #, P < 0.05 compared with O-1602 or LPI alone (ANOVA, with Bonferroni pos-test). (B) Mouse osteoclasts generated from wild-type macrophages (black bars) or GPR55−/− macrophages (white bars) were starved for 30 min and then were treated as above before measurement of Rho activation (n = 2 experiments).
Fig. 4.
Fig. 4.
Trabecular bone volume is increased in male GPR55−/− mice. (A) μCT reconstructions of trabecular bone in the distal tibial and proximal femoral metaphysis at 12 weeks of age, with mean percent BV/TV values. (B) Significant changes in trabecular number, trabecular pattern factor, and structure modulus index. Black bars indicate wild-type (WT) mice; white bars indicate GPR55−/− mice. Data are mean ± SEM from 8 wild-type and 4 GPR55−/− male and female mice. Student's t test; *, P < 0.05; **, P < 0.01 compared with wild type. (C) Sections of femora were stained with toluidine blue and Safranin O. Note the increased presence of cartilage remnants (orange) in the trabecular bone (blue) of the GPR55−/− mouse. Asterisks indicate bone marrow (purple); arrows indicate trabecular bone; C, chondrocytes. (Scale bar: 20 μm.)
See this image and copyright information in PMC

V体育ios版 - References

    1. Di Marzo V, Bifulco M, De Petrocellis L. The endocannabinoid system and its therapeutic exploitation. Nature Reviews Drug Discovery. 2004;3:771–784. - PubMed
    1. Idris AI, et al. Regulation of bone mass, bone loss and osteoclast activity by cannabinoid receptors. Nat Med. 2005;11:774–779. - PMC - PubMed
    1. Ofek O, et al. Peripheral cannabinoid receptor, CB2, regulates bone mass. Proc Natl Acad Sci USA. 2006;103:696–701. - VSports在线直播 - PMC - PubMed
    1. Begg M, et al. Evidence for novel cannabinoid receptors. Pharmacology and Therapeutics. 2005;106:133–145. - PubMed
    1. Baker D, Pryce G, Davies WL, Hiley CR. In silico patent searching reveals a new cannabinoid receptor. Trends Pharmacol Sci. 2006;27:1–4. - PubMed

Publication types

MeSH terms