Inhibiting Monoacylglycerol Lipase Suppresses RANKL-Induced Osteoclastogenesis and Alleviates Ovariectomy-Induced Bone Loss

Osteoporosis is a common chronic metabolic bone disease characterized by reduced trabecular bone and increased bone fragility. Monoacylglycerol lipase (MAGL) is a lipolytic enzyme to catalyze the hydrolysis of monoglycerides and specifically degrades the 2-arachidonoyl glycerol (2-AG). Previous studies have identified that 2-AG is the mainly source for arachidonic acid and the most abundant endogenous agonist of cannabinoid receptors. Considering the close relationship between inflammatory mediators/cannabinoid receptors and bone metabolism, we speculated that MAGL may play a role in the osteoclast differentiation. In the present study, we found that MAGL protein expression increased during osteoclast differentiation. MAGL knockdown by adenovirus-mediated shRNA in bone marrow-derived macrophages demonstrated the suppressive effects of MAGL on osteoclast formation and bone resorption. In addition, pharmacological inhibition of MAGL by JZL184 suppressed osteoclast differentiation, bone resorption, and osteoclast-specific gene expression. Activation of the Mitogen-activated protein kinase (MAPK) and nuclear factor κB (NF-κB) pathways was inhibited by JZL184 and deletion of MAGL. Our in vivo study indicated that JZL184 ameliorated bone loss in an ovariectomized mouse model. Furthermore, overexpressing H1 calponin partially alleviated the inhibition caused by JZL184 or MAGL deletion on osteoclastogenesis. Therefore, we conclude that targeting MAGL may be a novel therapeutic strategy for osteoporosis.

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Protective Effect of Ciclopirox against Ovariectomy-Induced Bone Loss in Mice by Suppressing Osteoclast Formation and Function

International Journal of Molecular Sciences ◽

10.3390/ijms22158299 ◽

2021 ◽

Vol 22 (15) ◽

pp. 8299

Author(s):

Hye Jung Ihn ◽

Jiwon Lim ◽

Kiryeong Kim ◽

Sang-Hyeon Nam ◽

Soomin Lim ◽

...

Keyword(s):

Bone Loss ◽

Type I Collagen ◽

Osteoclast Differentiation ◽

Osteoclast Formation ◽

Bone Diseases ◽

Mitogen Activated Protein Kinase ◽

Type I ◽

And Function

Postmenopausal osteoporosis is closely associated with excessive osteoclast formation and function, resulting in the loss of bone mass. Osteoclast-targeting agents have been developed to manage this disease. We examined the effects of ciclopirox on osteoclast differentiation and bone resorption in vitro and in vivo. Ciclopirox significantly inhibited osteoclast formation from primary murine bone marrow macrophages (BMMs) in response to receptor activator of nuclear factor kappa B ligand (RANKL), and the expression of genes associated with osteoclastogenesis and function was decreased. The formation of actin rings and resorption pits was suppressed by ciclopirox. Analysis of RANKL-mediated early signaling events in BMMs revealed that ciclopirox attenuates IκBα phosphorylation without affecting mitogen-activated protein kinase activation. Furthermore, the administration of ciclopirox suppressed osteoclast formation and bone loss in ovariectomy-induced osteoporosis in mice and reduced serum levels of osteocalcin and C-terminal telopeptide fragment of type I collagen C-terminus. These results indicate that ciclopirox exhibits antiosteoclastogenic activity both in vitro and in vivo and represents a new candidate compound for protection against osteoporosis and other osteoclast-related bone diseases.

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Biological Effects of β-Glucans on Osteoclastogenesis

Molecules ◽

10.3390/molecules26071982 ◽

2021 ◽

Vol 26 (7) ◽

pp. 1982

Author(s):

Wataru Ariyoshi ◽

Shiika Hara ◽

Ayaka Koga ◽

Yoshie Nagai-Yoshioka ◽

Ryota Yamasaki

Keyword(s):

Bone Resorption ◽

Bone Marrow Cells ◽

Biological Effects ◽

Osteoclast Differentiation ◽

Treatment Strategies ◽

Alcaligenes Faecalis ◽

Osteoclast Formation ◽

Osteoclast Precursors

Although the anti-tumor and anti-infective properties of β-glucans have been well-discussed, their role in bone metabolism has not been reviewed so far. This review discusses the biological effects of β-glucans on bone metabolisms, especially on bone-resorbing osteoclasts, which are differentiated from hematopoietic precursors. Multiple immunoreceptors that can recognize β-glucans were reported to be expressed in osteoclast precursors. Coordinated co-stimulatory signals mediated by these immunoreceptors are important for the regulation of osteoclastogenesis and bone remodeling. Curdlan from the bacterium Alcaligenes faecalis negatively regulates osteoclast differentiation in vitro by affecting both the osteoclast precursors and osteoclast-supporting cells. We also showed that laminarin, lichenan, and glucan from baker’s yeast, as well as β-1,3-glucan from Euglema gracilisas, inhibit the osteoclast formation in bone marrow cells. Consistent with these findings, systemic and local administration of β-glucan derived from Aureobasidium pullulans and Saccharomyces cerevisiae suppressed bone resorption in vivo. However, zymosan derived from S. cerevisiae stimulated the bone resorption activity and is widely used to induce arthritis in animal models. Additional research concerning the relationship between the molecular structure of β-glucan and its effect on osteoclastic bone resorption will be beneficial for the development of novel treatment strategies for bone-related diseases.

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Pristimerin Inhibits Osteoclast Differentiation and Bone Resorption in vitro and Prevents Ovariectomy-Induced Bone Loss in vivo

Drug Design Development and Therapy ◽

10.2147/dddt.s275128 ◽

2020 ◽

Vol Volume 14 ◽

pp. 4189-4203

Author(s):

Peng Sun ◽

Qichang Yang ◽

Yanben Wang ◽

Jiaxuan Peng ◽

Kangxian Zhao ◽

...

Keyword(s):

Bone Resorption ◽

Bone Loss ◽

Osteoclast Differentiation

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Hedgehog Inhibitors Suppress Osteoclastogenesis in In Vitro Cultures, and Deletion of Smo in Macrophage/Osteoclast Lineage Prevents Age-Related Bone Loss

International Journal of Molecular Sciences ◽

10.3390/ijms21082745 ◽

2020 ◽

Vol 21 (8) ◽

pp. 2745

Author(s):

Yukihiro Kohara ◽

Ryuma Haraguchi ◽

Riko Kitazawa ◽

Yuuki Imai ◽

Sohei Kitazawa

Keyword(s):

Bone Resorption ◽

Bone Loss ◽

Signaling Pathway ◽

Early Stage ◽

Osteoclast Differentiation ◽

Osteoclast Formation ◽

Age Related ◽

Hh Signaling

The functional role of the Hedgehog (Hh)-signaling pathway has been widely investigated in bone physiology/development. Previous studies have, however, focused primarily on Hh functions in bone formation, while its roles in bone resorption have not been fully elucidated. Here, we found that cyclopamine (smoothened (Smo) inhibitor), GANT-58 (GLI1 inhibitor), or GANT-61 (GLI1/2 inhibitor) significantly inhibited RANKL-induced osteoclast differentiation of bone marrow-derived macrophages. Although the inhibitory effects were exerted by cyclopamine or GANT-61 treatment during 0–48 h (early stage of osteoclast differentiation) or 48–96 h (late stage of osteoclast differentiation) after RANKL stimulation, GANT-58 suppressed osteoclast formation only during the early stage. These results suggest that the Smo-GLI1/2 axis mediates the whole process of osteoclastogenesis and that GLI1 activation is requisite only during early cellular events of osteoclastogenesis. Additionally, macrophage/osteoclast-specific deletion of Smo in mice was found to attenuate the aging phenotype characterized by trabecular low bone mass, suggesting that blockage of the Hh-signaling pathway in the osteoclast lineage plays a protective role against age-related bone loss. Our findings reveal a specific role of the Hh-signaling pathway in bone resorption and highlight that its inhibitors show potential as therapeutic agents that block osteoclast formation in the treatment of senile osteoporosis.

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Dihydroartemisinin prevents breast cancer-induced osteolysis via inhibiting both breast caner cells and osteoclasts

Scientific Reports ◽

10.1038/srep19074 ◽

2016 ◽

Vol 6 (1) ◽

Cited By ~ 20

Author(s):

Ming-Xuan Feng ◽

Jian-Xin Hong ◽

Qiang Wang ◽

Yong-Yong Fan ◽

Chi-Ting Yuan ◽

...

Keyword(s):

Breast Cancer ◽

Bone Resorption ◽

Molecular Mechanisms ◽

Osteoclast Differentiation ◽

Metastatic Breast ◽

Osteoclast Formation ◽

Migration And Invasion ◽

Titanium Particle

Abstract Bone is the most common site of distant relapse in breast cancer, leading to severe complications which dramatically affect the patients’ quality of life. It is believed that the crosstalk between metastatic breast cancer cells and osteoclasts is critical for breast cancer-induced osteolysis. In this study, the effects of dihydroartemisinin (DHA) on osteoclast formation, bone resorption, osteoblast differentiation and mineralization were initially assessed in vitro, followed by further investigation in a titanium-particle-induced osteolysis model in vivo. Based on the proved inhibitory effect of DHA on osteolysis, DHA was further applied to MDA-MB-231 breast cancer-induced mouse osteolysis model, with the underlying molecular mechanisms further investigated. Here, we verified for the first time that DHA suppressed osteoclast differentiation, F-actin ring formation and bone resorption through suppressing AKT/SRC pathways, leading to the preventive effect of DHA on titanium-particle-induced osteolysis without affecting osteoblast function. More importantly, we demonstrated that DHA inhibited breast tumor-induced osteolysis through inhibiting the proliferation, migration and invasion of MDA-MB-231 cells via modulating AKT signaling pathway. In conclusion, DHA effectively inhibited osteoclastogenesis and prevented breast cancer-induced osteolysis.

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A Bone-Targeting Enoxacin Delivery System to Eradicate Staphylococcus Aureus-Related Implantation Infections and Bone Loss

Frontiers in Bioengineering and Biotechnology ◽

10.3389/fbioe.2021.749910 ◽

2021 ◽

Vol 9 ◽

Author(s):

Cong Yao ◽

Meisong Zhu ◽

Xiuguo Han ◽

Qiang Xu ◽

Min Dai ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Bone Loss ◽

Bone Tissue ◽

Mesoporous Silica Nanoparticles ◽

Osteoclast Differentiation ◽

Osteoclast Formation ◽

Bacterial Biofilm ◽

Orthopaedic Implant

Post-operative infections in orthopaedic implants are severe complications that require urgent solutions. Although conventional antibiotics limit bacterial biofilm formation, they ignore the bone loss caused by osteoclast formation during post-operative orthopaedic implant-related infections. Fortunately, enoxacin exerts both antibacterial and osteoclast inhibitory effects, playing a role in limiting infection and preventing bone loss. However, enoxacin lacks specificity in bone tissue and low bioavailability-related adverse effects, which hinders translational practice. Here, we developed a nanosystem (Eno@MSN-D) based on enoxacin (Eno)-loaded mesoporous silica nanoparticles (MSN), decorated with the eight repeating sequences of aspartate (D-Asp8), and coated with polyethylene glycol The release results suggested that Eno@MSN-D exhibits a high sensitivity to acidic environment. Moreover, this Eno@MSN-D delivery nanosystem exhibited both antibacterial and anti-osteoclast properties in vitro. The cytotoxicity assay revealed no cytotoxicity at the low concentration (20 μg/ml) and Eno@MSN-D inhibited RANKL-induced osteoclast differentiation. Importantly, Eno@MSN-D allowed the targeted release of enoxacin in infected bone tissue. Bone morphometric analysis and histopathology assays demonstrated that Eno@MSN-D has antibacterial and antiosteoclastic effects in vivo, thereby preventing implant-related infections and bone loss. Overall, our study highlights the significance of novel biomaterials that offer new alternatives to treat and prevent orthopaedic Staphylococcus aureus-related implantation infections and bone loss.

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Grape Seed Proanthocyanidin Extract Prevents Bone Loss via Regulation of Osteoclast Differentiation, Apoptosis, and Proliferation

Nutrients ◽

10.3390/nu12103164 ◽

2020 ◽

Vol 12 (10) ◽

pp. 3164

Author(s):

Sung Chul Kwak ◽

Yoon-Hee Cheon ◽

Chang Hoon Lee ◽

Hong Young Jun ◽

Kwon-Ha Yoon ◽

...

Keyword(s):

Bone Loss ◽

Osteoclast Differentiation ◽

Grape Seed ◽

Mitogen Activated Protein Kinase ◽

Terminal Deoxynucleotidyl Transferase ◽

Nuclear Factor ◽

Systemic Injection ◽

Grape Seed Proanthocyanidin Extract ◽

Grape Seed Proanthocyanidin

Dietary procyanidin has been shown to be an important bioactive component that regulates various pharmacological activities to maintain metabolic homeostasis. In particular, grape seed proanthocyanidin extract (GSPE) is a commercially available medicine for the treatment of venous and lymphatic dysfunction. This study aimed to investigate whether GSPE protects against lipopolysaccharide (LPS)-induced bone loss in vivo and the related mechanism of action in vitro. The administration of GSPE restored the inflammatory bone loss phenotype stimulated by acute systemic injection of LPS in vivo. GSPE strongly suppressed receptor activator of nuclear factor kappa-B ligand (RANKL)-induced osteoclast differentiation and bone resorption activity of mature osteoclasts by decreasing the RANKL-induced nuclear factor-κB transcription activity. GSPE mediates this effect through decreased phosphorylation and degradation of NF-κB inhibitor (IκB) by IκB kinaseβ, subsequently inhibiting proto-oncogene cellular Fos and nuclear factor of activated T cells. Additionally, GSPE promotes osteoclast proliferation by increasing the phosphorylation of components of the Akt and mitogen-activated protein kinase signaling pathways and it also inhibits apoptosis by decreasing the activity of caspase-8, caspase-9, and caspase-3, as corroborated by a decrease in the Terminal deoxynucleotidyl transferase dUTP nick end labeling -positive cells. Our study suggests a direct effect of GSPE on the proliferation, differentiation, and apoptosis of osteoclasts and reveals the mechanism responsible for the therapeutic potential of GSPE in osteoclast-associated bone metabolism disease.

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Fermented Oyster Extract Prevents Ovariectomy-Induced Bone Loss and Suppresses Osteoclastogenesis

Nutrients ◽

10.3390/nu11061392 ◽

2019 ◽

Vol 11 (6) ◽

pp. 1392 ◽

Cited By ~ 4

Author(s):

Hye Jung Ihn ◽

Ju Ang Kim ◽

Soomin Lim ◽

Sang-Hyeon Nam ◽

So Hyeon Hwang ◽

...

Keyword(s):

Bone Loss ◽

Type I Collagen ◽

Therapeutic Option ◽

Osteoclast Differentiation ◽

Nuclear Factor Κb ◽

Osteoclast Formation ◽

Type I ◽

Bioactive Substances

There is growing interest in bioactive substances from marine organisms for their potential use against diverse human diseases. Osteoporosis is a skeletal disorder associated with bone loss primarily occurring through enhanced osteoclast differentiation and resorption. Recently, we reported the anti-osteoclastogenic activity of fermented Pacific oyster (Crassostrea gigas) extract (FO) in vitro. The present study focused on investigating the anti-osteoporotic efficacy of FO in bone loss prevention in an experimental animal model of osteoporosis and elucidating the mechanism underlying its effects. Oral administration of FO significantly decreased ovariectomy-induced osteoclast formation and prevented bone loss, with reduced serum levels of bone turnover biomarkers including osteocalcin and C-terminal telopeptide fragment of type I collagen C-terminus (CTX). FO significantly suppressed receptor activator of nuclear factor-κB ligand (RANKL)-induced differentiation of bone marrow-derived macrophages (BMMs) into osteoclasts and attenuated the induction of osteoclast-specific genes required for osteoclastogenesis and bone resorption. Furthermore, FO inhibited RANKL-mediated IκBα and p65 phosphorylation in BMMs. Taken together, these results demonstrate that FO effectively suppresses osteoclastogenesis in vivo and in vitro, and that FO can be considered as a potential therapeutic option for the treatment of osteoporosis and osteoclast-mediated skeletal diseases.

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Berberine Suppresses RANKL-Induced Osteoclast Differentiation by Inhibiting c-Fos and NFATc1 Expression

The American Journal of Chinese Medicine ◽

10.1142/s0192415x19500228 ◽

2019 ◽

Vol 47 (02) ◽

pp. 439-455 ◽

Cited By ~ 3

Author(s):

Sang-Yong Han ◽

Yun-Kyung Kim

Keyword(s):

Bone Loss ◽

Osteoclast Differentiation ◽

Osteoclast Formation ◽

Bone Diseases ◽

Mrna Levels ◽

Nuclear Factor ◽

Activated T Cells ◽

Murine Bone Marrow

Osteoporosis is a common disorder of bone remodeling, marked by excessive osteoclast formation. Recent studies indicated that berberine (BBR) is a potential natural drug for the treatment of various bone diseases. However, it still needs to be further studied for the treatment of osteoporosis. The current study investigated the inhibitory effects of BBR on receptor activator of nuclear factor-[Formula: see text]B ligand (RANKL)-induced osteoclast differentiation in vitro and in vivo. Cell-based assays were performed using osteoclasts generated in cultures of murine bone marrow-derived macrophages (BMMs) treated with RANKL and M-CSF. The effects of BBR on in vivo lipopolysaccharide (LPS)-mediated bone loss were evaluated using ICR mice. BBR significantly inhibited TRAP-positive osteoclast formation induced by RANKL. BBR also inhibited RANKL-induced Akt, p38 and ERK phosphorylation and I[Formula: see text]B degradation, and suppressed RANKL-induced expression of c-Fos and nuclear factor of activated T cells c1 (NFATc1), which is a key transcription factors for osteoclast formation. BBR reduced the mRNA levels of osteoclast markers, including TRAP, osteoclast-associated receptor (OSCAR), cathepsin K, and ATPase H[Formula: see text] transporting V0 subunit d2 (ATP6v0d2). Moreover, BBR prevented LPS-mediated bone loss in vivo. We suggest BBR as a natural compound that can be a potential therapeutic agent for osteoclast-related bone diseases.

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Ethanolic Extract of Rubus coreanus Fruits Inhibits Bone Marrow-Derived Osteoclast Differentiation and Lipopolysaccharide-Induced Bone Loss

Natural Product Communications ◽

10.1177/1934578x1701201228 ◽

2017 ◽

Vol 12 (12) ◽

pp. 1934578X1701201

Author(s):

Tae-Ho Kim ◽

Chae Gyeong Jeong ◽

Hyeong-U Son ◽

Man-Il Huh ◽

Shin-Yoon Kim ◽

...

Keyword(s):

Bone Marrow ◽

Bone Resorption ◽

Bone Loss ◽

Osteoclast Differentiation ◽

Ethanolic Extract ◽

Type I ◽

Mineral Density ◽

Induced Differentiation ◽

Rubus Coreanus

The inhibition of osteoclast differentiation/bone resorption is a well-known therapeutic strategy for controlling pathological and postmenopausal bone loss. Natural products that specifically inhibit osteoclastogenesis could therefore be developed as antiresorptive drugs for the treatment of metabolic bone disorders characterized by excessive osteoclastic bone resorption. We therefore examined the effects of Rubus coreanus extract (eeRc) on receptor activator of nuclear factor kappa-B ligand (RANKL)-induced differentiation of bone marrow macrophages (BMMs) into osteoclasts and pit formation in vitro. Additionally, the in vivo effects of the eeRc were observed in mice with lipopolysaccharide (LPS)-induced bone erosion. In this study, we found that the ethanolic extract of Rubus coreanus fruits considerably suppressed the RANKL-induced differentiation of primary BMMs into osteoclasts and bone-resorbing activity of mature osteoclasts. Oral administration of eeRc attenuated LPS-induced bone loss in vivo, as demonstrated by the reversal of LPS-induced reduction in bone volume per tissue volume, bone mineral density, and trabecular number to some extent in eeRc-treated mice. In addition, eeRc slightly decreased the serum levels of C-terminal telopeptide fragments of type I collagen, the collagen-breakdown product generated by osteoclasts. Collectively, our results indicate that eeRc has the potential to inhibit bone loss by blocking osteoclast differentiation and could therefore be a promising natural product for the prevention and/or treatment of inflammatory bone loss.

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