Isopsoralen ameliorates H2O2-induced damage in osteoblasts via activating the Wnt/β-catenin pathway

Angelicin improves osteoporosis in ovariectomized rats by reducing ROS production in osteoclasts through regulation of the KAT6A/Nrf2 signalling pathway

BACKGROUND

Angelicin, which is found in Psoralea, can help prevent osteoporosis by stopping osteoclast formation, although the precise mechanism remains unclear.

METHODS

We evaluated the effect of angelicin on the oxidative stress level of osteoclasts using ovariectomized osteoporosis model rats and RAW264.7 cells. Changes in the bone mass of the femur were investigated using H&E staining and micro-CT. ROS content was investigated by DHE fluorescence labelling. Osteoclast-related genes and proteins were examined for expression using Western blotting, immunohistochemistry, tartrate-resistant acid phosphatase staining, and real-time quantitative PCR. The influence of angelicin on osteoclast development was also evaluated using the MTT assay, double luciferin assay, chromatin immunoprecipitation, immunoprecipitation and KAT6A siRNA transfection.

RESULTS

Rats treated with angelicin had considerably higher bone mineral density and fewer osteoclasts. Angelicin prevented RAW264.7 cells from differentiating into osteoclasts in vitro when stimulated by RANKL. Experiments revealed reduced ROS levels and significantly upregulated intracellular KAT6A, HO-1, and Nrf2 following angelicin treatment. The expression of genes unique to osteoclasts, such as MMP9 and NFATc1, was also downregulated. Finally, KAT6A siRNA transfection increased intracellular ROS levels while decreasing KAT6A, Nrf2, and HO-1 protein expression in osteoclasts. However, in the absence of KAT6A siRNA transfection, angelicin greatly counteracted this effect in osteoclasts.

CONCLUSIONS

Angelicin increased the expression of KAT6A. This enhanced KAT6A expression helps to activate the Nrf2/HO-1 antioxidant stress system and decrease ROS levels in osteoclasts, thus inhibiting oxidative stress levels and osteoclast formation.

Exploring quality evaluation markers of Fructus Psoraleae based on chemometric analysis integrated with network pharmacology

INTRODUCTION

Fructus Psoraleae (FP) is a well-known traditional Chinese medicine for the treatment of osteoporosis. However, major quality differences were witnessed owing to its various origins, thus influencing its safety and efficacy.

OBJECTIVES

The study aimed to evaluate the quality of FP from different origins and predict its quality evaluation markers.

METHODS

Ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry was employed for tentative characterisation of the constituents in 10 batches of FP, followed by the utilisation of multivariate statistical analysis methods including principal component analysis and orthogonal partial least squares discriminant analysis for quality evaluation. Network pharmacology approaches were utilised to explore the underlying mechanism of the screened chemotaxonomic markers in treating osteoporosis.

RESULTS

Forty-one components in FP including, chalcones, coumarins, coumestans, flavonoids, iso-flavonoids, and phenolics, were characterised based on their fragmentation pathways. Ten batches of FP were basically divided into three categories, and eight chemotaxonomic markers including isopsoralen, calamenene, bakuchiol, psoralen, bavachinin, isoneobavaisoflavone, corylifol C, and neobavaisoflavone were screened. Network pharmacology revealed that the chemotaxonomic markers can act on targets such as AKT1, HSP90AA1, and EGFR and possess effects mainly through glycolysis and wnt/β-catenin signalling to alleviate osteoporosis. Molecular docking and molecular dynamic simulation confirmed the good binding affinity and stability between proteins and selected markers. So, eight chemotaxonomic markers were all preferentially recommended as quality evaluation markers.

CONCLUSION

The study not only provides a reference for the improvement of quality control of FP but also offers a theoretical basis for its further in-depth research in osteoporosis.

Advances in the study of traditional Chinese medicine affecting bone metabolism through modulation of oxidative stress

Bone metabolic homeostasis is dependent on coupled bone formation dominated by osteoblasts and bone resorption dominated by osteoclasts, which is a process of dynamic balance between bone formation and bone resorption. Notably, the formation of bone relies on the development of bone vasculature. Previous studies have shown that oxidative stress caused by disturbances in the antioxidant system of the whole organism is an important factor affecting bone metabolism. The increase in intracellular reactive oxygen species can lead to disturbances in bone metabolism, which can initiate multiple bone diseases, such as osteoporosis and osteoarthritis. Traditional Chinese medicine is considered to be an effective antioxidant. Cumulative evidence shows that the traditional Chinese medicine can alleviate oxidative stress-mediated bone metabolic disorders by modulating multiple signaling pathways, such as Nrf2/HO-1 signaling, PI3K/Akt signaling, Wnt/β-catenin signaling, NF-κB signaling, and MAPK signaling. In this paper, the potential mechanisms of traditional Chinese medicine to regulate bone me-tabolism through oxidative stress is summarized to provide direction and theoretical basis for future research related to the treatment of bone diseases with traditional Chinese medicine.

A study on the anti-osteoporosis mechanism of isopsoralen based on network pharmacology and molecular experiments

OBJECTIVE

Osteoporosis (OP) is a disease caused by multiple factors. Studies have pointed out that isopsoralen (IPRN) is one of the most effective drugs for the treatment of OP. Based on network pharmacological and molecular experimental analysis, the molecular mechanism of IPRN in osteoporosis is clarified.

METHODS

IPRN target genes and OP-related genes were predicted from the databases. Intersections were obtained and visualized. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were performed on target genes, which was confirmed by experiments internal and external experiments. Molecular docking was used to verify the binding between IPRN and target proteins. Molecular dynamics (MD) simulates the binding affinity of protein targets and active compounds.

RESULTS

87 IPRN target genes and 242 disease-related targets were predicted. The protein-protein interaction (PPI) network identified 18 IPRN target proteins for the treatment of OP. GO analysis indicated that target genes were involved in biological processes. KEGG analysis showed that pathways such as PI3K/AKT/mTOR were associated with OP. Cell experiments (qPCR and WB) found that the expressions of PI3K, AKT, and mTOR in MC3T3-E1 cells at 10 μM, 20 μM, and 50 μM IPRN concentrations, especially at 20 μM IPRN treatment, were higher than those in the control group at 48 h. Animal experiments also showed that compared with the control group, 40 mg/kg/time IPRN could promote the expression of the PI3K gene in chondrocytes of SD rats.

CONCLUSIONS

This study predicted the target genes of IPRN in the treatment of OP and preliminarily verified that IPRN plays an anti-OP role through the PI3K/AKT/mTOR pathway, which provides a new drug for the treatment of OP.

Isopsoralen suppresses receptor activator of nuclear factor kappa-β ligand-induced osteoclastogenesis by inhibiting the NF-κB signaling

Osteoporosis is a serious systemic metabolic bone system disease.This study aimed to identify the target genes of isopsoralen and the signaling pathways involved in the differential expression of the genes involved in osteoclast differentiation. We hypothesized that isopsoralen may inhibit osteoclast differentiation by blocking the nuclear factor kappa-B (NF-κB) signaling pathway and verified our hypothesis through basic experiments. The 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay was used to detect the effect of isopsoralen on the proliferation and viability of primary mouse bone marrow monocytes (BMMCs). The effect of isopsoralen on receptor activator of nuclear factor kappa-B ligand (RANKL)-induced osteoclast differentiation was determined by using tartrate-resistant acid phosphatase (TRAP) staining. Quantitative real-time PCR (qRT-PCR) and Western blot were used to detect the expression of the related genes and proteins. The Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway of isopsoralen target genes were obtained through comprehensive analysis using the STITCH database, Cytoscape 3.8.2, and R-Studio software. Differentially expressed genes (DEGs) were found in osteoclasts induced by RANKL before and after 3 days using R-Studio, following which KEGG analysis was performed. Next, enrichment analysis was performed on the KEGG pathway shared by the target genes of isopsoralen and the differentially expressed genes during osteoclast differentiation to predict the signaling pathway underlying the inhibition of osteoclast differentiation by isopsoralen. Finally, Western blot was used to detect the effect of isopsoralen on the activation of signaling pathways to verify the results of our bioinformatics analysis. Based on the enrichment analysis of isopsoralen target genes and differentially expressed genes during osteoclastogenesis, we believe that isopsoralen can inhibit RANKL-induced osteoclastogenesis by inhibiting the NF-κB signaling pathway.

Anti-Postmenopausal osteoporosis effects of Isopsoralen: A bioinformatics-integrated experimental study

Isopsoralen (IPRN), which comes from the fruit of Psoralea corylifolia, has been identified as a kind of phytoestrogen and has been proven to be effective for the treatment of osteoporosis (OP). However, the mechanisms underlying IPRN's anti-OP effects, especially the anti-postmenopausal osteoporosis (PMOP) effects, remain indistinct. Thus, this study aimed to investigate the effects and mechanisms of IPRN's anti-PMOP activity. In this study, the bioinformatics results predicted that IPRN could resist PMOP by targeting EGFR, AKT1, SRC, CCND1, ESR1 (ER-α), AR, PGR, BRCA1, PTGS2, and IGF1R. An ovariectomized (OVX) mice model and a H₂ O₂ -induced bone marrow mesenchyml stem cells (BMSCs) model confirmed that IPRN could inhibit the bone loss induced by OVX in mice and promote the osteogenic differentiation in H₂ O₂ -induced BMSCs by inhibiting oxidative stress and apoptosis. Moreover, IPRN could significantly produce the above effects by upregulating ESR1. IPRN might be a therapeutic agent for PMOP by acting as an estrogen replacement agent and a natural antioxidant.

Phytochemicals Mediate Autophagy Against Osteoarthritis by Maintaining Cartilage Homeostasis

Osteoarthritis (OA) is a common degenerative joint disease and is a leading cause of disability and reduced quality of life worldwide. There are currently no clinical treatments that can stop or slow down OA. Drugs have pain-relieving effects, but they do not slow down the course of OA and their long-term use can lead to serious side effects. Therefore, safe and clinically appropriate long-term treatments for OA are urgently needed. Autophagy is an intracellular protective mechanism, and targeting autophagy-related pathways has been found to prevent and treat various diseases. Attenuation of the autophagic pathway has now been found to disrupt cartilage homeostasis and plays an important role in the development of OA. Therefore, modulation of autophagic signaling pathways mediating cartilage homeostasis has been considered as a potential therapeutic option for OA. Phytochemicals are active ingredients from plants that have recently been found to reduce inflammatory factor levels in cartilage as well as attenuate chondrocyte apoptosis by modulating autophagy-related signaling pathways, which are not only widely available but also have the potential to alleviate the symptoms of OA. We reviewed preclinical studies and clinical studies of phytochemicals mediating autophagy to regulate cartilage homeostasis for the treatment of OA. The results suggest that phytochemicals derived from plant extracts can target relevant autophagic pathways as complementary and alternative agents for the treatment of OA if subjected to rigorous clinical trials and pharmacological tests.

Anti-Cancer and Anti-Inflammatory Potential of Furanocoumarins from Ammi majus L

Secondary metabolites have potential benefits to human being. They are used in the food, agricultural and pharmaceutical industries. The secondary metabolite of furanocoumarins from different plant sources is essential in various skin-related ailments. Biologically, these chemicals are isolated from different plants in the Apiaceae, Fabaceae, Rutaceae and Moraceae families. Ammi Majus L. is one of the most common plants in the family of Apiaceae with a large quantity of derivatives. The furanocoumarin derivatives defend the plant by fighting external enemies by systemic acquired resistance (SAR). Via suppressing or retarding microbial growth in infected parts, these derivatives, along with SAR, help to alleviate inflammation in the human body. Latest evidence of these compounds has been established in the treatment of cancer, but the mechanism that needs to be elaborated is not yet understood. Recent studies have shown that furanocoumarin derivatives bind to DNA base pairs and block DNA replication. This may be a potential pathway that helps to regulate the growth of cancerous cells. This article reflects on the pharmaceutical data of furanocoumarins and their different mechanisms in these cases.

Angelicin Alleviates Post-Trauma Osteoarthritis Progression by Regulating Macrophage Polarization via STAT3 Signaling Pathway

Post-trauma osteoarthritis (PTOA) is the most common articular disease characterized by degeneration and destruction of articular cartilage (Bultink and Lems, Curr. Rheumatol Rep., 2013, 15, 328). Inflammatory response of local joint tissue induced by trauma is the most critical factor accelerating osteoarthritis (OA) progression (Sharma et al., 2019; Osteoarthritis. Cartilage, 28, 658–668). M1/M2 macrophages polarization and repolarization participates in local inflammation, which plays a major role in the progression of OA (Zhang et al., 2018; Ann. Rheum. Dis., 77, 1524–1534). The regulating effect of macrophage polarization has been reported as a potential therapy to alleviate OA progression. Synovitis induced by polarized macrophages could profoundly affect the chondrocyte and cartilage matrix (Zhang et al., 2018; Ann. Rheum. Dis., 77, 1524–1534). Generally, anti-inflammatory medications widely used in clinical practice have serious side effects. Therefore, we focus on exploring a new therapeutic strategy with fewer side effects to alleviate the synovitis. Angelicin (ANG) is traditional medicine used in various folk medicine. Previous studies have revealed that angelicin has an inhibitory effect on inflammation (Wei et al., 2016; Inflammation, 39, 1876–1882), tumor growth (Li et al., 2016; Oncology reports, 36, 3,504–3,512; Wang et al., 2017; Molecular Medicine Reports, 16, 5441–5449), DNA damage (Li et al., 2019; Exp. Ther. Med., 18, 1899–1906), and virus proliferation (Li et al., 2018; Front. Cell. Infect. Microbiol., 8, 178). But its specific effects on influencing the process of OA were rarely reported. In this study, the molecular mechanism of angelicin in vivo and in vitro was clearly investigated. Results showed that angelicin could regulate the M1/M2 ratio and function and alleviate the development of PTOA in the meanwhile. Bone marrow monocytes were isolated and induced by macrophage colony-stimulating factor (M-CSF), lipopolysaccharide (LPS) and interferon (IFN)-γ for M1 polarization and interleukin (IL)-4/IL-13 for M2 polarization. Subsequently, repolarization intervention was performed. The results indicate that angelicin can repolarize M1 toward M2 macrophages by upregulating the expression of CD9. Besides, angelicin can also protect and maintain M2 polarization in the presence of LPS/IFN-γ, and subsequently downregulate the expression of inflammatory mediators such as IL-1β and TNF-α. Mechanistically, angelicin can activate the p-STAT3/STAT3 pathway by conducting CD9/gp130 to repolarize toward M2 macrophages. These results suggest angelicin can alleviate the progression of OA by regulating M1/M2 polarization via the STAT3/p-STAT3 pathway. Therefore, angelicin may have a promising application and potential therapeutic value in OA clinical treatment.

Protection of Icariin Against Hydrogen Peroxide-Induced MC3T3-E1 Cell Oxidative Damage

Objective

The aim of the present study was to evaluate the potential protective mechanism of icariin against oxidative damage caused by hydrogen peroxide in MC3T3‐E1 cells.

Methods

MC3T3‐E1 cells were treated with different concentrations of icariin to explore the optimal dose of icariin. MC3T3‐E1 cells were divided into groups treated with various concentrations of hydrogen peroxide (H₂O₂; 0, 0.1, 0.2, 0.5, 1, and 2 mM) for 24 h to induce oxidative damage and cell viability was assessed by Cell Counting Kit‐8 (CCK‐8) assay. Then, cells were divided into five groups: control, H₂O₂ (0.2 mM), icariin (0.1 μM) and H₂O₂ (0.2 mM), + icariin (0.1 μM). Cell viability was detected by CCK‐8 assay. In addition, the content of glutathione and superoxide dismutase and the activity level of malondialdehyde in these treatment groups were determined. Alkaline phosphatase (ALP) and alizarin red S (ARS) staining were also performed to measure the early and late osteogenesis, respectively. Protein expression of β‐catenin and cyclin D1 was measured by western blot assay. Then, we used an antagonist of Wnt/β‐catenin signaling pathway (DKK‐1) and western blot analysis to further explore potential mechanism.

Results

After 24 h of exposure to 0.2 mM H₂O₂, the viability of MC3T3‐E1 cells was significantly decreased compared to that of the control cells. We first found that icariin can promote cell proliferation of MC3T3‐E1 cells in a dose‐dependent manner, with the dosage 0.1 μM showing the best pro‐proliferative effect. Furthermore, icariin could promote the protein expression of OSX and RUNX2. The results showed that icariin can reverse the inhibitory osteogenic effects of MC3T3‐E1 caused by H₂O₂. In addition, icariin could increase the Wnt‐signaling related proteins. The results showed that MC3T3‐E1 cells in the H₂O₂ (0.2 mM) + icariin (0.1 μM) + Wnt‐signaling antagonist (DKK‐1) group had weaker ALP and ARS staining compared with that observed in the control and H₂O₂ (0.2 mM) + icariin (0.1 μM) groups. The ALP activity and calcium content were decreased in the 0.2 mM H₂O₂ + 0.1 μM icariin + DKK‐1 group compared to that observed in the 0.2 mM H₂O₂ + 0.1 μM icariin group.

Conclusion

The results showed that icariin can increase the viability of MC3T3‐E1 cells, reverse the oxidative stress induced by H₂O₂ and protect MC3T3‐E1 cells against H₂O₂‐induced inhibition of osteogenic differentiation, which may occur through the Wnt/β‐catenin signaling pathway.

Cytoprotective effects of fermented oyster extracts against oxidative stress-induced DNA damage and apoptosis through activation of the Nrf2/HO-1 signaling pathway in MC3T3-E1 osteoblasts

Osteoblast damage by oxidative stress has been recognized as a cause of bone-related disease, including osteoporosis. Recently, we reported that fermented Pacific oyster (Crassostrea gigas) extracts (FO) inhibited osteoclastogenesis and osteoporosis, while promoting osteogenesis. However, since the beneficial potential of FO on osteoblasts is not well known, in the present study, we investigated the cytoprotective effect of FO against oxidative stress in MC3T3-E1 osteoblasts. Our results demonstrated that FO inhibited hydrogen peroxide (H2O2)-induced DNA damage and cytotoxicity through the rescue of mitochondrial function by blocking abnormal ROS accumulation. FO also prevented apoptosis by suppressing loss of mitochondrial membrane potential and cytosolic release of cytochrome c, decreasing the rate of Bax/Bcl-2 expression and reducing the activity of caspase-9 and caspase-3 in H2O2-stimulated MC3T3-E1 osteoblasts, suggesting that FO protected MC3T3-E1 osteoblasts from the induction of caspase dependent- and mitochondria-mediated apoptosis by oxidative stress. In addition, FO markedly promoted the activation of nuclear factor-erythroid-2-related factor 2 (Nrf2), which was associated with the enhanced expression of heme oxygenase-1 (HO-1). However, inhibiting the expression of HO-1 by artificially blocking the expression of Nrf2 using siRNA significantly eliminated the protective effect of FO, indicating that FO activates the Nrf2/HO-1 signaling pathway in MC3T3-E1 osteoblasts to protect against oxidative stress. Based on the present data, FO is thought to be useful as a potential therapeutic agent for the inhibition of oxidative stress in osteoblasts.

MiR-708 inhibits MC3T3-E1 cells against H2O2-induced apoptosis through targeting PTEN

Background

The dysregulation of proliferation and apoptosis plays a significant role in the pathogenesis of postmenopausal osteoporosis (PO). MicroRNAs play an important role in regulating apoptosis of MC3T3-E1 cells. However, the role and potential mechanism of miR-708 for regulating H₂O₂-induced apoptosis is unknown. This study aimed to investigate the protective function of miR-708 in H₂O₂-induced apoptosis of MC3T3-E1 osteoblasts.

Methods

MC3T3-E1 was co-cultured with H₂O₂ for 8 h, then, flow cytometry, malondialdehyde (MDA), and glutathione peroxidase (Gpx) levels were measured to establish the oxidative model. MiRNA microarray was performed to assess differentially expressed miRNAs between control and H₂O₂-treated MC3T3-E1 cells. We then performed RT-PCR to identify the relative expression of miR-708 and PTEN. After transfected MC3T3-E1 with miR-708 mimics, flow cytometry, MDA, and Gpx level were performed to identify the apoptosis rate and oxidative stress in these groups. Furthermore, we small interfering RNA of PTEN to identify the role of PTEN in H₂O₂-induced apoptosis of MC3T3-E1 cells.

Results

H₂O₂ (100 nM) could significantly induce the apoptosis of MC3T3-E1 cells. Moreover, H₂O₂ could significantly increase the MDA level and downregulated Gpx level. RT-PCR found that H₂O₂ significantly decrease the level of miR-708. Compared with H₂O₂ group, H₂O₂ + miR-708 mimic significantly decreased the apoptosis rate.

Conclusions

miR-708 plays a protective role in H₂O₂-induced MC3T3-E1 osteoblasts apoptosis and its protective effect is proceeded by regulating ROS level and PTEN expression level.

Angelicin-A Furocoumarin Compound With Vast Biological Potential

Angelicin, a member of the furocoumarin group, is related to psoralen which is well known for its effectiveness in phototherapy. The furocoumarins as a group have been studied since the 1950s but only recently has angelicin begun to come into its own as the subject of several biological studies. Angelicin has demonstrated anti-cancer properties against multiple cell lines, exerting effects via both the intrinsic and extrinsic apoptotic pathways, and also demonstrated an ability to inhibit tubulin polymerization to a higher degree than psoralen. Besides that, angelicin too demonstrated anti-inflammatory activity in inflammatory-related respiratory and neurodegenerative ailments via the activation of NF-κB pathway. Angelicin also showed pro-osteogenesis and pro-chondrogenic effects on osteoblasts and pre-chondrocytes respectively. The elevated expression of pro-osteogenic and chondrogenic markers and activation of TGF-β/BMP, Wnt/β-catenin pathway confirms the positive effect of angelicin bone remodeling. Angelicin also increased the expression of estrogen receptor alpha (ERα) in osteogenesis. Other bioactivities, such as anti-viral and erythroid differentiating properties of angelicin, were also reported by several researchers with the latter even displaying an even greater aptitude as compared to the commonly prescribed drug, hydroxyurea, which is currently on the market. Apart from that, recently, a new application for angelicin against periodontitis had been studied, where reduction of bone loss was indirectly caused by its anti-microbial properties. All in all, angelicin appears to be a promising compound for further studies especially on its mechanism and application in therapies for a multitude of common and debilitating ailments such as sickle cell anaemia, osteoporosis, cancer, and neurodegeneration. Future research on the drug delivery of angelicin in cancer, inflammation and erythroid differentiation models would aid in improving the bioproperties of angelicin and efficacy of delivery to the targeted site. More in-depth studies of angelicin on bone remodeling, the pro-osteogenic effect of angelicin in various bone disease models and the anti-viral implications of angelicin in periodontitis should be researched. Finally, studies on the binding of angelicin toward regulatory genes, transcription factors, and receptors can be done through experimental research supplemented with molecular docking and molecular dynamics simulation.

Electromagnetic field treatment increases purinergic receptor P2X7 expression and activates its downstream Akt/GSK3β/β-catenin axis in mesenchymal stem cells under osteogenic induction

Background

Imbalance in bone formation and resorption is a crucial component of the pathological process leading to osteoporosis. Electromagnetic fields (EMFs) have been reported to be beneficial to osteogenesis, although the exact mechanism has not been fully clarified. Purinergic receptor P2X7 is expressed in osteoblasts and is reported to participate in the regulation of bone metabolism.

Objectives

To elucidate the link between EMFs and P2X7 expression and investigate its potential as a novel therapeutic target in osteoporosis.

Method

We investigated the effect of EMFs on P2X7 expression and downstream signaling in human bone marrow mesenchymal stem cells (h-MSCs). We also established an ovariectomized (OVX) osteoporosis rat model to evaluate the therapeutic efficacy of combining EMFs with P2X7 agonists.

Results

EMF treatment increased P2X7 expression in h-MSCs under conditions of osteogenic induction but not under regular culture conditions. P2X7 or PI3K/Akt inhibition partially inhibited the pro-osteogenic effect of EMF and lowered the EMF-stimulated activity of the Akt/GSK3β/β-catenin axis. No additive effect of this suppression was observed following simultaneous inhibition of P2X7 and PI3K/Akt. EMF treatment in the presence of a P2X7 agonist had a greater effect in increasing osteogenic marker expression than that of EMF treatment alone. In the OVX osteoporosis model, the therapeutic efficacy of combining EMFs with P2X7 agonists was superior to that of EMF treatment alone.

Conclusions

EMF treatment increases P2X7 expression by h-MSCs during osteogenic differentiation, leading to activation of the Akt/GSK3β/β-catenin axis, which promotes the osteogenesis. Our findings also indicate that combined EMF and P2X7 agonist treatment may be an effective novel strategy for osteoporosis therapy.