The cannabinoid receptor I (CB1) enhanced the osteogenic differentiation of BMSCs by rescue impaired mitochondrial metabolism function under inflammatory condition

Abstract

Background Periodontitis is a chronic infectious disease leading to bone resorption and periodontal tissue disruption under inflammatory stimulation. The osteogenic differentiation ability of mesenchymal stem cells (MSCs) is impaired under the inflammatory environment, which limits the effect of treatment. The cannabinoid receptor I (CB1) is the main effector of the endogenous cannabinoid system (ECS), and our previous study verified that CB1 could enhance the osteo/dentinogenic differentiation of dental MSCs, which might be a target for alveolar bone regeneration. However, the effect of CB1 on the osteogenic differentiation of MSCs derived from bone remains unknown. In present study, we investigated the role and mechanism of CB1 on mitochondrial function and osteogenic differentiation of human bone marrow mesenchymal stem cells (hBMSCs) under inflammatory environment. Methods Alkaline phosphatase (ALP) activity, alizarin red staining, quantitative calcium analysis, and osteogenic markers were used to detect the osteogenic differentiation ability of BMSCs. Real-time RT-PCR and Western blot were used to detect the gene expression. Seahorse Cell Mito Stress Test was used to detect the oxygen consumption rate (OCR). JC-10 assay was used to determine the mitochondrial membrane potential (MMP). Results CB1 increased osteogenic differentiation potential and mitochondrial energy metabolism, including the OCR, MMP, and enhanced the expressions of Nrf1 and Nrf2 in hBMSCs without or with TNF-α or INF-γ stimulation. Then, the inhibitor of mitochondrial electron transport chain (ETC), rotenone (ROT), inhibited the osteogenic differentiation in hBMSCs, and CB1 could rescue ROT impaired osteogenic differentiation potentials of hBMSCs without or with TNF-α or INF-γ stimulation. Activation of ETC by Coenzyme Q10 (CoQ10) could restore the impaired osteogenic differentiation of hBMSCs by depletion of CB1 without or with TNF-α or INF-γ stimulation. Mechanismly, CB1 could activate the JNK signaling pathway, p38 MAPK signaling pathway, and inhibit the Erk1/2 signaling pathway. Conclusions The activating of CB1 enhanced the osteogenic differentiation by rescuing the mitochondrial metabolism function in hBMSCs under the inflammatory environment, suggesting that CB1 is a potential target for enhancing bone regeneration under the inflammatory environment.

Involvement of the endocannabinoid system in current and recurrent periodontitis: A human study

“…These data confirm the involvement of CB1 and CB2, and of the epithelium associated with periodontal inflammation, in line with the results of previous research 22,24 . Studies observed that cannabinoid receptors seem to play a role in the promotion of periodontal tissue healing by the improvement of fibroblast adhesion and migration, and by enhancing the osteo/dentinogenic differentiation of periodontal ligament stem cells even during tissue inflammation 17,24,31,32 . According to our results, inflammation does not seem to impact predominantly on one of the two receptors.…”

“…22,24 Studies observed that cannabinoid receptors seem to play a role in the promotion of periodontal tissue healing by the improvement of fibroblast adhesion and migration, and by enhancing the osteo/dentinogenic differentiation of periodontal ligament stem cells even during tissue inflammation. 17,24,31,32 According to our results, inflammation does not seem to impact predominantly on one of the two receptors. Literature reports that CB1 receptors are mainly located in the central and peripheric nervous system, but it also has been found partially expressed in periodontal tissue as well as testis, retina, bone, adipocytes, heart, lung, prostate, spleen, uterus and ovaries.…”

Regulation of the Host Immune Microenvironment in Periodontitis and Periodontal Bone Remodeling

“…However, the regulatory mechanism of MSCs in an inflammatory microenvironment remains controversial. Some studies have found that the inflammatory cytokines IFN-γ, TNF-α and IL-1β can inhibit the osteogenic differentiation, immunoregulation and proliferation functions of MSCs [ 84 , 85 , 86 ], whereas other studies have shown that low levels of inflammatory stimulation, such as with the stimulation of LPS, the immunomodulatory properties of mBMSCs were increased. Moreover, the expression of collagen I and osteocalcin (OCN) in human PDLSCs were downregulated under Pg-LPS stimulation conditions, and calcium formation was decreased in mBMSCs by LPS at 1 μg/mL [ 87 , 88 , 89 ].…”

The role of Nrf2 in periodontal disease by regulating lipid peroxidation, inflammation and apoptosis

“…It is reported that the differentiation of MSCs is often accompanied by mitochondrial biogenesis, which is controlled by PGC-1 α and further activates Nrf1, Nrf2 and mtTFA expression in coordination with γ polymerase to promote mtDNA replication. The increased expression of Nrf1 and Nrf2 can increase the mitochondrial biogenesis of hBMSCs, thus enhancing the osteogenic differentiation potential of hBMSCs ( 94 , 95 ). FNDC5-pretreated BMSC-Exos were also shown to have anti-inflammatory effects and promote M2 macrophage polarization through the NF-κB signaling pathway and the Nrf2/HO-1 axis ( 96 ).…”