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.

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 Roles of monocarboxylate transporter subtypes in promotion and suppression of osteoclast differentiation and survival on bone

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Hiroko Imai ◽  
Kentaro Yoshimura ◽  
Yoichi Miyamoto ◽  
Kiyohito Sasa ◽  
Marika Sugano ◽  
...  
Keyword(s):  
Bone Resorption ◽  
Osteoclast Differentiation ◽  
Osteoclast Formation ◽  
Hydroxycinnamic Acid ◽  
Negative Regulator ◽  
Gene Knockdown ◽  
Monocarboxylate Transporter ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Lactate And Pyruvate

Abstract Monocarboxylate transporters (MCTs) provide transmembrane transport of monocarboxylates such as lactate and pyruvate. The present results showed that α-cyano-4-hydroxycinnamic acid (CHC), an inhibitor of MCTs, promoted osteoclast differentiation from macrophages at lower concentrations (0.1–0.3 mM) and suppressed that at a higher concentration (1.0 mM). On the other hand, CHC reduced the number of mature osteoclasts on the surface of dentin in a concentration-dependent manner. Additionally, macrophages and osteoclasts were found to express the Mct1, Mct2, and Mct4 genes, with Mct1 and Mct4 expression higher in macrophages, and that of Mct2 higher in osteoclasts. Although Mct1 gene knockdown in macrophages enhanced osteoclast formation induced by RANKL, Mct2 gene knockdown suppressed that. Finally, Mct2 gene silencing in mature osteoclasts decreased their number and, thereby, bone resorption. These results suggest that MCT1 is a negative regulator and MCT2 a positive regulator of osteoclast differentiation, while MCT2 is required for bone resorption by osteoclasts.

scholarly journals Concentration and Duration of Indoxyl Sulfate Exposure Affects Osteoclastogenesis by Regulating NFATc1 via Aryl Hydrocarbon Receptor

2020 ◽  
Vol 21 (10) ◽  
pp. 3486 ◽  
Author(s):  
Wen-Chih Liu ◽  
Jia-Fwu Shyu ◽  
Paik Seong Lim ◽  
Te-Chao Fang ◽  
Chien-Lin Lu ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Aryl Hydrocarbon Receptor ◽  
Critical Role ◽  
Osteoclast Differentiation ◽  
Indoxyl Sulfate ◽  
Raw 264.7 Cells ◽  
High Dose ◽  
Activated T Cells ◽  
Aryl Hydrocarbon

Indoxyl sulfate (IS) is a chronic kidney disease (CKD)-specific renal osteodystrophy metabolite that affects the nuclear factor of activated T-cells, cytoplasmic 1 (NFATc1), a transcription factor promoting osteoclastogenesis. However, the mechanisms underlying the regulation of NFATc1 by IS remain unknown. It is intriguing that the Aryl hydrocarbon receptor (AhR) plays a key role in osteoclastogenesis, since IS is an endogenous AhR agonist. This study investigates the relationship between IS concentration and osteoclast differentiation in Raw 264.7 cells, and examines the effects of different IS concentrations on NFATc1 expression through AhR signaling. Our data suggest that both osteoclastogenesis and NFATc1 are affected by IS through AhR signaling in both dose- and time-dependent manners. Osteoclast differentiation increases with short-term, low-dose IS exposure and decreases with long-term, high-dose IS exposure. Different IS levels switch the role of AhR from that of a ligand-activated transcription factor to that of an E3 ubiquitin ligase. We found that the AhR nuclear translocator may play an important role in the regulation of these dual functions of AhR under IS treatment. Altogether, this study demonstrates that the IS/AhR/NFATc1 signaling axis plays a critical role in osteoclastogenesis, indicating a potential role of AhR in the pathology and abnormality of bone turnover in CKD patients.

scholarly journals Claudin 18 is a novel negative regulator of bone resorption and osteoclast differentiation

2012 ◽  
Vol 27 (7) ◽  
pp. 1553-1565 ◽  
Author(s):  
Gabriel R Linares ◽  
Robert Brommage ◽  
David R Powell ◽  
Weirong Xing ◽  
Shin-Tai Chen ◽  
...  
Keyword(s):  
Bone Resorption ◽  
Osteoclast Differentiation ◽  
Negative Regulator

scholarly journals HDAC2 regulates FoxO1 during RANKL-induced osteoclastogenesis

2016 ◽  
Vol 310 (10) ◽  
pp. C780-C787 ◽  
Author(s):  
Ce Dou ◽  
Nan Li ◽  
Ning Ding ◽  
Chuan Liu ◽  
Xiaochao Yang ◽  
...  
Keyword(s):  
Bone Resorption ◽  
Osteoclast Differentiation ◽  
Nuclear Factor Κb ◽  
Negative Regulator ◽  
Bone Homeostasis ◽  
Akt Activation ◽  
Histone Deacetylase 2 ◽  
Forkhead Box ◽  
Receptor Activator ◽  
And Function

The bone-resorbing osteoclast (OC) is essential for bone homeostasis, yet deregulation of OCs contributes to diseases such as osteoporosis, osteopetrosis, and rheumatoid arthritis. Here we show that histone deacetylase 2 (HDAC2) is a key positive regulator during receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclastogenesis and bone resorption. Bone marrow macrophages (BMMs) showed increased HDAC2 expression during osteoclastogenesis. HDAC2 overexpression enhanced, whereas HDAC2 deletion suppressed osteoclastogenesis and bone resorption using lentivirus infection. Mechanistically, upon RANKL activation, HDAC2 activated Akt; Akt directly phosphorylates and abrogates Forkhead box protein O1 (FoxO1), which is a negative regulator during osteoclastogenesis through reducing reactive oxygen species. HDAC2 deletion in BMMs resulted in decreased Akt activation and increased FoxO1 activity during osteoclastogenesis. In conclusion, HDAC2 activates Akt thus suppresses FoxO1 transcription results in enhanced osteoclastogenesis. Our data imply the potential value of HDAC2 as a new target in regulating osteoclast differentiation and function.

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