scholarly journals Mutant p62P392L Stimulation of Osteoclast Differentiation in Paget's Disease of Bone

Endocrinology ◽  
2011 ◽  
Vol 152 (11) ◽  
pp. 4180-4189 ◽  
Author(s):  
Kumaran Sundaram ◽  
Srinivasan Shanmugarajan ◽  
D. Sudhaker Rao ◽  
Sakamuri V. Reddy
Keyword(s):  
Bone Resorption ◽  
Osteoclast Differentiation ◽  
Paget’S Disease ◽  
Paget's Disease ◽  
Mouse Bone Marrow ◽  
Nuclear Factor ◽  
Activated T Cells ◽  
Retroviral Transduction ◽  
Sequestosome 1 ◽  
Rank Signaling

Paget's disease of the bone (PDB) is an autosomal dominant trait with genetic heterogeneity, characterized by abnormal osteoclastogenesis. Sequestosome 1 (p62) is a scaffold protein that plays an important role in receptor activator of nuclear factor κB (RANK) signaling essential for osteoclast (OCL) differentiation. p62P392L mutation in the ubiquitin-associated (UBA) domain is widely associated with PDB; however, the mechanisms by which p62P392L stimulate OCL differentiation in PDB are not completely understood. Deubiquitinating enzyme cylindromatosis (CYLD) has been shown to negatively regulate RANK ligand-RANK signaling essential for OCL differentiation. Here, we report that CYLD binds with the p62 wild-type (p62WT), non-UBA mutant (p62A381V) but not with the UBA mutant (p62P392L) in OCL progenitor cells. Also, p62P392L induces expression of c-Fos (2.8-fold) and nuclear factor of activated T cells c1 (6.0-fold) transcription factors critical for OCL differentiation. Furthermore, p62P392L expression results in accumulation of polyubiquitinated TNF receptor-associated factor (TRAF)6 and elevated levels of phospho-IκB during OCL differentiation. Retroviral transduction of p62P392L/CYLD short hairpin RNA significantly increased TRAP positive multinucleated OCL formation/bone resorption activity in mouse bone marrow cultures. Thus, the p62P392L mutation abolished CYLD interaction and enhanced OCL development/bone resorption activity in PDB.

scholarly journals Osteoclastic Metabolism of 25(OH)-Vitamin D3: A Potential Mechanism for Optimization of Bone Resorption

Endocrinology ◽  
2010 ◽  
Vol 151 (10) ◽  
pp. 4613-4625 ◽  
Author(s):  
Masakazu Kogawa ◽  
David M. Findlay ◽  
Paul H. Anderson ◽  
Renee Ormsby ◽  
Cristina Vincent ◽  
...  
Keyword(s):  
T Cells ◽  
Bone Resorption ◽  
Mononuclear Cells ◽  
Osteoclast Differentiation ◽  
Raw264.7 Cells ◽  
Marker Genes ◽  
Null Mouse ◽  
Nuclear Factor ◽  
Activated T Cells ◽  
Mouse Splenocytes

The extrarenal synthesis of 1α,25 dihydroxyvitamin D3 (1,25D) has been demonstrated in a number of cell types including osteoblasts and cells of the monocyte/macrophage lineage. The skeleton appears responsive to serum levels of the 1,25D precursor, 25 hydroxyvitamin D3 (25D), in terms of bone mineralization parameters. The effect of metabolism of 25D into active 1,25D by osteoclast lineage cells is unknown. We found that CYP27B1 mRNA expression increased with exposure of human peripheral blood mononuclear cells (PBMCs) to macrophage colony-stimulating factor in the presence or absence of receptor activator of nuclear factor-κB ligand. Consistent with this, human osteoclast cultures incubated with 25D produced measurable quantities of 1,25D. Osteoclast formation from either mouse RAW264.7 cells or human PBMCs in the presence of physiological concentrations of 25D resulted in significant up-regulation of the key osteoclast transcription factor, nuclear factor of activated T cells-c1 in PBMCs and a number of key osteoclast marker genes in both models. The expression of the osteoblast coupling factor, ephrin-b2, was also increased in the presence of 25D. Levels of CYP27B1 and nuclear factor of activated T cells-1 mRNA correlated during osteoclastogenesis and also in a cohort of human bone samples. CYP27B1 short-hairpin RNA knockdown in RAW264.7 cells decreased their osteoclastogenic potential. 25D dose dependently reduced the resorptive capacity of PBMC-derived osteoclasts without compromising cell viability. 25D also reduced resorption by RAW264.7- and giant cell tumor-derived osteoclasts. Conversely, osteoclasts formed from vitamin D receptor-null mouse splenocytes had increased resorptive activity compared with wild-type cells. We conclude that 25D metabolism is an important intrinsic mechanism for optimizing osteoclast differentiation, ameliorating osteoclast activity, and potentially promoting the coupling of bone resorption to formation.

scholarly journals Endogenous Collagenases Regulate Osteoclast Fusion

Biomolecules ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 705
Author(s):  
Hyo Jeong Kim ◽  
Youngkyun Lee
Keyword(s):  
Present Report ◽  
Osteoclast Differentiation ◽  
Nuclear Factor Κb ◽  
Mouse Bone Marrow ◽  
Nuclear Factor ◽  
Activated T Cells ◽  
Extracellular Signal ◽  
Mouse Bone Marrow Macrophage ◽  
Collagenase Inhibition ◽  
And Function

The precise regulation of osteoclast differentiation and function is crucial for the maintenance of healthy bone. Despite several reports of collagenase expression in bone tissues, the precise isoform expression as well as the role in osteoclasts are still unclear. In the present report, the expression of matrix metalloprotease (MMP)8 and MMP13 was confirmed in mouse bone marrow macrophage osteoclast precursors. The mRNA and protein expressions of both collagenases were significantly reduced by receptor activator of nuclear factor κB ligand (RANKL) stimulation. Notably, either inhibition of MMP expression by siRNA or treatment of cells with collagenase inhibitor Ro 32-3555 significantly augmented osteoclast fusion and resorption activity without affecting the osteoclast number. The inhibition of collagenase by Ro 32-3555 increased the expression of osteoclast fusion genes, Atp6v0d2 and Dcstamp, without affecting nuclear factor of activated T-cells, cytoplasmic 1 (NFATc1) protein expression. The enhanced osteoclast fusion by collagenase inhibition appears to be mediated through an extracellular signal regulated kinase (ERK)-dependent pathway. Collectively, these data provide novel information on the regulation of osteoclast fusion process.

scholarly journals Eudebeiolide B Inhibits Osteoclastogenesis and Prevents Ovariectomy-Induced Bone Loss by Regulating RANKL-Induced NF-κB, c-Fos and Calcium Signaling

2020 ◽  
Vol 13 (12) ◽  
pp. 468
Author(s):  
Mi-Hwa Kim ◽  
Hyung-Jin Lim ◽  
Seon Gyeong Bak ◽  
Eun-Jae Park ◽  
Hyun-Jae Jang ◽  
...  
Keyword(s):  
Bone Loss ◽  
Calcium Signaling ◽  
Osteoblast Differentiation ◽  
Transmembrane Protein ◽  
Osteoclast Differentiation ◽  
Mouse Bone Marrow ◽  
Nuclear Factor ◽  
Mineral Density ◽  
Activated T Cells

Eudebeiolide B is a eudesmane-type sesquiterpenoid compound isolated from Salvia plebeia R. Br., and little is known about its biological activity. In this study, we investigated the effects of eudebeiolide B on osteoblast differentiation, receptor activator nuclear factor-κB ligand (RANKL)-induced osteoclastogenesis in vitro and ovariectomy-induced bone loss in vivo. Eudebeiolide B induced the expression of alkaline phosphatase (ALP) and calcium accumulation during MC3T3-E1 osteoblast differentiation. In mouse bone marrow macrophages (BMMs), eudebeiolide B suppressed RANKL-induced osteoclast differentiation of BMMs and bone resorption. Eudebeiolide B downregulated the expression of nuclear factor of activated T-cells 1 (NFATc1) and c-fos, transcription factors induced by RANKL. Moreover, eudebeiolide B attenuated the RANKL-induced expression of osteoclastogenesis-related genes, including cathepsin K (Ctsk), matrix metalloproteinase 9 (MMP9) and dendrocyte expressed seven transmembrane protein (DC-STAMP). Regarding the molecular mechanism, eudebeiolide B inhibited the phosphorylation of Akt and NF-κB p65. In addition, it downregulated the expression of cAMP response element-binding protein (CREB), Bruton’s tyrosine kinase (Btk) and phospholipase Cγ2 (PLCγ2) in RANKL-induced calcium signaling. In an ovariectomized (OVX) mouse model, intragastric injection of eudebeiolide B prevented OVX-induced bone loss, as shown by bone mineral density and contents, microarchitecture parameters and serum levels of bone turnover markers. Eudebeiolide B not only promoted osteoblast differentiation but inhibited RANKL-induced osteoclastogenesis through calcium signaling and prevented OVX-induced bone loss. Therefore, eudebeiolide B may be a new therapeutic agent for osteoclast-related diseases, including osteoporosis, rheumatoid arthritis and periodontitis.

HSP90 inhibitors enhance differentiation and MITF (microphthalmia transcription factor) activity in osteoclast progenitors

2013 ◽  
Vol 451 (2) ◽  
pp. 235-244 ◽  
Author(s):  
A. Gabrielle J. van der Kraan ◽  
Ryan C. C. Chai ◽  
Preetinder P. Singh ◽  
Benjamin J. Lang ◽  
Jiake Xu ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Transforming Growth Factor ◽  
Osteoclast Differentiation ◽  
Osteoclast Formation ◽  
Mouse Bone Marrow ◽  
Nuclear Factor ◽  
Hsp90 Inhibitors ◽  
Activated T Cells ◽  
Atpase Subunit ◽  
Protein Levels

The HSP90 (heat-shock protein 90) inhibitor 17-AAG (17-allylamino-demethoxygeldanamycin) increases osteoclast formation both in vitro and in vivo, an action that can enhance cancer invasion and growth in the bone microenvironment. The cellular mechanisms through which 17-AAG exerts this action are not understood. Thus we sought to clarify the actions of 17-AAG on osteoclasts and determine whether other HSP90 inhibitors had similar properties. We determined that 17-AAG and the structurally unrelated HSP90 inhibitors CCT018159 and NVP-AUY922 dose-dependently increased RANKL [receptor activator of NF-κB (nuclear factor κB) ligand]-stimulated osteoclastogenesis in mouse bone marrow and pre-osteoclastic RAW264.7 cell cultures. Moreover, 17-AAG also enhanced RANKL- and TNF (tumour necrosis factor)-elicited osteoclastogenesis, but did not affect RANKL-induced osteoclast survival, suggesting that only differentiation mechanisms are targeted. 17-AAG affected the later stages of progenitor maturation (after 3 days of incubation), whereas the osteoclast formation enhancer TGFβ (transforming growth factor β) acted prior to this, suggesting different mechanisms of action. In studies of RANKL-elicited intracellular signalling, 17-AAG treatment did not increase c-Fos or NFAT (nuclear factor of activated T-cells) c1 protein levels nor did 17-AAG increase activity in luciferase-based NF-κB- and NFAT-response assays. In contrast, 17-AAG treatment (and RANKL treatment) increased both MITF (microphthalmia-associated transcription factor) protein levels and MITF-dependent vATPase-d2 (V-type proton ATPase subunit d2) gene promoter activity. These results indicate that HSP90 inhibitors enhance osteoclast differentiation in an NFATc1-independent manner that involves elevated MITF levels and activity.

scholarly journals TGFβ1 Regulates Human RANKL-Induced Osteoclastogenesis via Suppression of NFATc1 Expression

2020 ◽  
Vol 21 (3) ◽  
pp. 800 ◽  
Author(s):  
Tokunaga ◽  
Mokuda ◽  
Kohno ◽  
Yukawa ◽  
Kuranobu ◽  
...  
Keyword(s):  
Bone Resorption ◽  
Transforming Growth Factor ◽  
Nuclear Translocation ◽  
Osteoclast Differentiation ◽  
Magnetic Bead ◽  
Tartrate Resistant Acid Phosphatase ◽  
Nuclear Factor ◽  
Blood Monocytes ◽  
Activated T Cells ◽  
Gene And Protein Expression

Osteoclasts are multinucleated giant cells responsible for bone resorption. Various mediators involved in osteoclast differentiation have been investigated as possible therapeutic targets for osteoporosis and rheumatoid arthritis (RA). Although transforming growth factor beta1 (TGFβ1) has been described as one such multifunctional cytokine essential for bone remodeling, its effect on osteoclastogenesis remains controversial. Therefore, we sought to examine the effect of TGFβ1 on osteoclast generation induced by receptor activator of nuclear factor (NF)-κB ligand (RANKL) in humans. Peripheral blood monocytes, isolated using magnetic bead sorting, were cultured with macrophage-colony stimulating factor (M-CSF) or RANKL with or without TGFβ1. Tartrate-resistant acid phosphatase (TRAP) staining, as well as bone resorption assays, revealed that TGFβ1 suppressed RANKL-mediated human osteoclast development. Real-time reverse transcription PCR and Western blotting revealed that TGFβ1 reduced the gene and protein expression of nuclear factor of activated T cells, cytoplasmic 1 (NFATc1), the master regulator of osteoclast differentiation, respectively. Luciferase assays indicated that TGFβ1 inhibited the NF-κB p65-stimulated promoter activity of NFATc1. Immunofluorescence analysis demonstrated that TGFβ1 abrogated RANKL-induced nuclear translocation of p65. Thus, TGFβ1 regulates human RANKL-induced osteoclastogenesis via downregulation of NFATc1 by blocking nuclear translocation of NF-κB, suggesting that TGFβ1 may be a potential therapeutic target for RA.

scholarly journals 4-Acetylantroquinonol B Inhibits Osteoclastogenesis by Inhibiting the Autophagy Pathway in a Simulated Microgravity Model

2020 ◽  
Vol 21 (18) ◽  
pp. 6971
Author(s):  
Chia-Hsin Wu ◽  
Ching-Huei Ou ◽  
I-Chuan Yen ◽  
Shih-Yu Lee
Keyword(s):  
Bone Resorption ◽  
Transmembrane Protein ◽  
Osteoclast Differentiation ◽  
Osteoclast Formation ◽  
Tartrate Resistant Acid Phosphatase ◽  
Nuclear Factor ◽  
Actin Ring ◽  
Activated T Cells ◽  
Cycle Arrest ◽  
Trap Staining

Astronauts suffer from 1–2% bone loss per month during space missions. Targeting osteoclast differentiation has been regarded as a promising strategy to prevent osteoporosis in microgravity (μXg). 4-acetylantroquinonol B (4-AAQB), a ubiquinone from Antrodia cinnamomea, has shown anti-inflammatory and anti-hepatoma activities. However, the effect of 4-AAQB on μXg-induced osteoclastogenesis remains unclear. In this study, we aimed to explore the mechanistic impact of 4-AAQB on osteoclast formation under μXg conditions. The monocyte/macrophage-like cell line RAW264.7 was exposed to simulated μXg (Rotary Cell Culture System; Synthecon, Houston, TX, USA) for 24 h and then treated with 4-AAQB or alendronate (ALN) and osteoclast differentiation factor receptor activator of nuclear factor kappa-B ligand (RANKL). Osteoclastogenesis, bone resorption activity, and osteoclast differentiation-related signaling pathways were analyzed using tartrate-resistant acid phosphatase (TRAP) staining, actin ring fluorescent staining, bone resorption, and western blotting assays. Based on the results of TRAP staining, actin ring staining, and bone resorption assays, we found that 4-AAQB significantly inhibited μXg-induced osteoclast differentiation. The critical regulators of osteoclast differentiation, including nuclear factor of activated T-cells cytoplasmic 1 (NFATc1), c-Fos, and dendritic cell-specific transmembrane protein (DC-STAMP), were consistently decreased. Meanwhile, osteoclast apoptosis and cell cycle arrest were also observed along with autophagy suppression. Interestingly, the autophagy inhibitors 3-methyladenine (3-MA) and chloroquine (CQ) showed similar effects to 4-AAQB. In conclusion, we suggest that 4-AAQB may serve as a potential agent against μXg-induced osteoclast formation.

scholarly journals TNF-induced osteoclastogenesis and inflammatory bone resorption are inhibited by transcription factor RBP-J

2012 ◽  
Vol 209 (2) ◽  
pp. 319-334 ◽  
Author(s):  
Baohong Zhao ◽  
Shannon N. Grimes ◽  
Susan Li ◽  
Xiaoyu Hu ◽  
Lionel B. Ivashkiv
Keyword(s):  
Transcription Factor ◽  
Bone Resorption ◽  
B Lymphocyte ◽  
Osteoclast Differentiation ◽  
Negative Regulator ◽  
Transcriptional Repressors ◽  
Recognition Sequence ◽  
Activated T Cells ◽  
Maturation Protein ◽  
Rank Signaling

Tumor necrosis factor (TNF) plays a key role in the pathogenesis of inflammatory bone resorption and associated morbidity in diseases such as rheumatoid arthritis and periodontitis. Mechanisms that regulate the direct osteoclastogenic properties of TNF to limit pathological bone resorption in inflammatory settings are mostly unknown. Here, we show that the transcription factor recombinant recognition sequence binding protein at the Jκ site (RBP-J) strongly suppresses TNF-induced osteoclastogenesis and inflammatory bone resorption, but has minimal effects on physiological bone remodeling. Myeloid-specific deletion of RBP-J converted TNF into a potent osteoclastogenic factor that could function independently of receptor activator of NF-κB (RANK) signaling. In the absence of RBP-J, TNF effectively induced osteoclastogenesis and bone resorption in RANK-deficient mice. Activation of RBP-J selectively in osteoclast precursors suppressed inflammatory osteoclastogenesis and arthritic bone resorption. Mechanistically, RBP-J suppressed induction of the master regulator of osteoclastogenesis (nuclear factor of activated T cells, cytoplasmic 1) by attenuating c-Fos activation and suppressing induction of B lymphocyte–induced maturation protein-1, thereby preventing the down-regulation of transcriptional repressors such as IRF-8 that block osteoclast differentiation. Thus, RBP-J regulates the balance between activating and repressive signals that regulate osteoclastogenesis. These findings identify RBP-J as a key upstream negative regulator of osteoclastogenesis that restrains excessive bone resorption in inflammatory settings.

Orostachys japonicus Suppresses Osteoclast Differentiation by Inhibiting NFATc1 Expression

2015 ◽  
Vol 43 (05) ◽  
pp. 1013-1030 ◽  
Author(s):  
Ki-Shuk Shim ◽  
Hyunil Ha ◽  
Taesoo Kim ◽  
Chung-Jo Lee ◽  
Jin Yeul Ma
Keyword(s):  
Bone Resorption ◽  
Bone Loss ◽  
Therapeutic Potential ◽  
Osteoclast Differentiation ◽  
Water Extract ◽  
Bone Diseases ◽  
Tartrate Resistant Acid Phosphatase ◽  
Dependent Manner ◽  
Nuclear Factor ◽  
Activated T Cells

The herb Orostachys japonicus has been traditionally used to treat chronic diseases, such as hepatitis, hemorrhoids, and cancer, in Asia. In this study, we investigated the effect of Orostachys japonicus water extract (OJWE) on the receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclast differentiation and bone loss. We found that OJWE inhibited RANKL-induced osteoclast differentiation in a dose-dependent manner without affecting bone resorption in bone marrow-derived macrophage cells. Interestingly, OJWE significantly reduced serum levels of C-terminal telopeptide of type 1 collagen and tartrate-resistant acid phosphatase (TRAP) 5b, markers of bone resorption and osteoclast number, respectively, in an animal model of bone loss. Furthermore, OJWE suppressed the RANKL-induced up-regulation of nuclear factor of activated T cells cytoplasmic 1 (NFATc1) expression, and activation of the p38 signaling pathway, but prevented the RANKL-mediated down-regulation of interferon regulatory factor-8 (IRF-8), which is known to be an anti-osteoclastogenic factor that represses NFATc1 expression. We also identified gallic acid and quercetin-3-O-β-D-glucoside as the OJWE components that inhibit RANKL-induced osteoclast differentiation. These results suggest that OJWE inhibits osteoclast differentiation by inhibiting RANKL-induced NFATc1 expression, which prevents osteoclast differentiation and bone loss. The present study elucidated a mechanism of action underlying the inhibitory effect of OJWE on osteoclast differentiation. Our findings suggest that O. japonicus has therapeutic potential for use in the treatment of bone diseases.

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