Inhibition of intravacuolar acidification by antisense RNA decreases osteoclast differentiation and bone resorption in vitro

1999 ◽  
Vol 112 (21) ◽  
pp. 3657-3666 ◽  
Author(s):  
T. Laitala-Leinonen ◽  
C. Lowik ◽  
S. Papapoulos ◽  
H.K. Vaananen

The role of proton transport and production in osteoclast differentiation was studied in vitro by inhibiting the transcription/translation of carbonic anhydrase II (CA II) and vacuolar H(+)-ATPase (V-ATPase) by antisense RNA molecules. Antisense RNAs targeted against CA II, or the 16 kDa or 60 kDa subunit of V-ATPase were used to block the expression of the specific proteins. A significant decrease in bone resorption rate and TRAP-positive osteoclast number was seen in rat bone marrow cultures and fetal mouse metacarpal cultures after antisense treatment. Intravacuolar acidification in rat bone marrow cells was also significantly decreased after antisense treatment. The CA II antisense RNA increased the number of TRAP-positive mononuclear cells, suggesting inhibition of osteoclast precursor fusion. Antisense molecules decreased the number of monocytes and macrophages, but increased the number of granulocytes in marrow cultures. GM-CSF, IL-3 and IL-6 were used to stimulate haematopoietic stem cell differentiation. The 16 kDa V-ATPase antisense RNA abolished the stimulatory effect of GM-CSF, IL-3 and IL-6 on TRAP-positive osteoclast formation, but did not affect the formation of monocytes and macrophages after IL-3 treatment, or the formation of granulocytes after IL-6 treatment. These results suggest that CA II and V-ATPase are needed, not only for the actual resorption, but also for osteoclast formation in vitro.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 629-629 ◽  
Author(s):  
Suzanne Lentzsch ◽  
Gulsum Anderson ◽  
Noriyoshi Kurihara ◽  
Tadashi Honjo ◽  
Judith Anderson ◽  
...  

Abstract CC-4047 (Actimid) is an immunomodulatory analog of thalidomide that has stronger anti-myeloma and anti-angiogenic activity than thalidomide, but its effects on human osteoclast lineage are unknown. Early osteoclast progenitors are of hematopoietic origin and progressively differentiate into mature bone resorbing multinucleated osteoclasts. We investigated the effects of CC-4047 and thalidomide on human osteoclastogenesis, using in vitro receptor activator of NFκ-B ligand/M-CSF stimulated culture system of bone marrow cells. Three weeks of treatment of primary bone marrow cultures with 100 μM CC-4047 decreased osteoclast formation accompanied by complete inhibition of bone resorption. Interestingly, osteoclast formation was also inhibited when cultures were treated with CC-4047 only for the first week (90% inhibition). In contrast, inhibitory effect was greatly diminished when the drug was given for only the last week (25% inhibition), indicating that inhibition of osteoclast formation is an early event. The inhibitory effect of CC-4047 on osteoclastogenesis was not induced by cell death, but by a shift of lineage commitment to granulocyte-CFU at the expense of GM-CFU that are osteoclast progenitors. Further studies revealed that this shift is mediated through down regulation of the transcription factor PU.1, which is critical for early osteoclast formation. In contrast to CC-4047, thalidomide was a significantly less potent inhibitor of osteoclast formation and bone resorption. These results provide the first evidence that CC-4047 blocks osteoclast differentiation at the early phase of osteoclastogenesis. Therefore, CC-4047 might be a valuable drug targeting both the tumor and osteoclastic activity in patients with multiple myeloma and potentially other diseases associated with the development of osteolytic lesions.


Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 1982
Author(s):  
Wataru Ariyoshi ◽  
Shiika Hara ◽  
Ayaka Koga ◽  
Yoshie Nagai-Yoshioka ◽  
Ryota Yamasaki

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.


2020 ◽  
Vol 21 (8) ◽  
pp. 2745
Author(s):  
Yukihiro Kohara ◽  
Ryuma Haraguchi ◽  
Riko Kitazawa ◽  
Yuuki Imai ◽  
Sohei Kitazawa

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.


2016 ◽  
Vol 118 (4) ◽  
pp. 914-923 ◽  
Author(s):  
Erxia Du ◽  
Patrick McAllister ◽  
Venugopal Reddy Venna ◽  
Liping Xiao

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Ming-Xuan Feng ◽  
Jian-Xin Hong ◽  
Qiang Wang ◽  
Yong-Yong Fan ◽  
Chi-Ting Yuan ◽  
...  

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.


1999 ◽  
Vol 78 (10) ◽  
pp. 1617-1623 ◽  
Author(s):  
N. Tani-Ishii ◽  
A. Tsunoda ◽  
T. Teranaka ◽  
T. Umemoto

Bone resorption is regulated by the cytokines within marrow cells that mediate osteoclast formation and activation. IL-1 and TNF induce bone resorption by stimulating the production of osteoclast-like multinucleated cells and by increasing the bone-resorbing activity of formed osteoclasts. This study was designed to detect IL-1 and TNF in osteoclasts in vitro and to determine whether these cytokines up-regulate osteoclast differentiation and bone resorption. The production of IL-1α, -β, and TNFa, β in osteoclasts was examined immunohistochemically and by in situ hybridization. In the co-culture of C57BL/6N mouse bone marrow and MC3T3-G2/PA6 cells, a colony of osteoclasts formed, and IL-1α and TNFa were detected. However, IL-1β and TNF β were not detected. To investigate the role of IL-1α and TNFα from osteoclasts, we enumerated TRAP-positive cells and measured the resorption pit areas in the presence of antibodies against IL-1α and TNFα. The addition of antibodies against IL-1α and TNFα to the co-culture system decreased the number of TRAP-positive colonies at seven days after incubation (anti-IL-1α, 25.0 ± 2.3%; anti-TNFα, 41.7 ± 3.7%; anti-IL-1α + anti-TNFα, 40.5 ± 1.3%; and control, 100%), and the ratio of mononuclear to multinuclear cells had changed (anti-IL-1α, 90:10; anti-TNFα, 75:25; anti-IL-1α+ anti-TNFα, 88:12; and control, 60:40). The total pit areas per dentin slice also decreased with the addition of antibodies (anti-IL-1α, 28,828; anti-TNFα, 49,249; anti-IL-1α + anti-TNFα, 30,685; and control, 303,139 mm2). These results suggest that local production of IL-la and TNFα by osteoclasts is an important mechanism for regulating the osteoclast differentiation and bone resorptive process.


2019 ◽  
Author(s):  
Lixin Xiang ◽  
Li Chen ◽  
Yang Xiang ◽  
Fengjie Li ◽  
Xiaomei Zhang ◽  
...  

AbstractRadiation induces rapid bone loss and enhances bone resorption and RANKL expression. RANKL provides the crucial signal to induce osteoclast differentiation and plays an important role in bone resorption. However, the mechanisms of radiation-induced osteoporosis are not fully understood. Here, we show that Crif1 expression increases in bone marrow cells after radiation. Conditional Crif1 deletion in bone marrow cells causes decreases in RANKL expression and the RANKL/OPG ratio, and relieves bone loss after radiation in mice. We further demonstrated in vitro that Crif1 promotes RANKL secretion via the cAMP/PKA pathway. Moreover, protein-protein docking screening identified five compounds as Crif1 inhibitors; these compounds dramatically suppressed RANKL secretion and CREB phosphorylation when cells were exposed to forskolin. This study enriches current knowledge of the pathogenesis of osteoporosis and provides insights into potential therapeutic strategies for osteoporosis treatment.


2018 ◽  
Vol 49 (4) ◽  
pp. 1512-1522
Author(s):  
Jiezhong Deng ◽  
Dong Sun ◽  
Fei Luo ◽  
Qiang Zhang ◽  
Feifan Chen ◽  
...  

Background/Aims: Tuberculosis induces bone loss and activates Th1 cells that play an important role in the host defense of Bacille Calmette-Guérin tuberculosis vaccine. However, the role of tuberculosis-activated Th1 cells in differentiation of osteoclast precursors to osteoclasts is unclear. As secretion of IFN-γ in Th1 cells is induced by tuberculosis, we aimed to investigate the role of anti-IFN-γ antibody on the differentiation and activation of osteoclasts in bone marrow monocyte-derived macrophages (BMMs). Methods: BMMs were isolated and co-cultured with CD4+T helper 1 cells (Th1 cells), pretreated with anti-IFN-γ antibody. Then, cell proliferation, expression and release of cytokines, formation of actin ring, differentiation of osteoclasts and bone resorption function were measured by CCK8 assay, qRT-PCR/Western blot/flow cytometry, ELISA, immunofluorescence, tartrate-resistant acidic phosphatase (TRAP) staining and bone absorbance assay, respectively. Results: Anti-IFN-γ antibody inhibited the cell viability of BMMs, and induced the expressions of RANKL, TNF-α, NF-κB and TRAF6 in BMMs. In addition, it led to increased expression levels of RANK on cell surfaces, and increased production of RANKL, TNF-α, MCP-1 and SDF-1. Anti-IFN-γ antibody also induced the expression of osteoclast differentiation factor and actin ring formation, but inhibited the expression of osteoprotegerin. TRAP staining and bone resorption assays showed that anti-IFN-γ antibody induced an increase in osteoclast formation and bone resorption. Conclusion: The anti-IFN-γ antibody induced osteoclast formation, and is probably mediated by RANKL-induced activation of NF-κB, that induces TRAF6 in the RANKL-RANK signaling pathway. Our data suggest an inhibitory role for IFN-γ in osteoclast formation induced by tuberculosis.


Author(s):  
Fanzi Wu ◽  
Boer Li ◽  
Xuchen Hu ◽  
Fanyuan Yu ◽  
Yu Shi ◽  
...  

The imbalance between bone formation and bone resorption causes osteoporosis, which leads to severe bone fractures. It is known that increases in osteoclast numbers and activities are the main reasons for increasing bone resorption. Although extensive studies have investigated the regulation of osteoclastogenesis of bone marrow macrophages (BMMs), new pharmacological avenues still need to be unveiled for clinical purpose. Wnt ligands have been widely demonstrated as stimulators of bone formation; however, the inhibitory effect of the Wnt pathway in osteoclastogenesis is largely unknown. Here, we demonstrate that Wnt7b, a potent Wnt ligand that enhances bone formation and increases bone mass, also abolishes osteoclastogenesis in vitro. Importantly, enforced expression of Wnt in bone marrow macrophage lineage cells significantly disrupts osteoclast formation and activity, which leads to a dramatic increase in bone mass. Mechanistically, Wnt7b impacts the glucose metabolic process and AKT activation during osteoclastogenesis. Thus, we demonstrate that Wnt7b diminishes osteoclast formation, which will be beneficial for osteoporosis therapy in the future.


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