scholarly journals Inorganic Pyrophosphate Promotes Osteoclastogenic Commitment and Survival of Bone Marrow Derived Monocytes mediated by Egr-1 up-regulation and MITF phosphorylation

2020 ◽  
Author(s):  
Samir M. Abdelmagid ◽  
Allison Zajac ◽  
Imad Salhab ◽  
Hyun-Duck Nah
Keyword(s):  
Bone Marrow ◽  
Bone Resorption ◽  
Osteoblast Differentiation ◽  
Ex Vivo ◽  
Osteoclast Differentiation ◽  
Mouse Bone Marrow ◽  
Matrix Mineralization ◽  
Inorganic Pyrophosphate ◽  
And Function

ABSTRACTSeveral reports emphasized the importance of inorganic pyrophosphate (PPi) in hindering osteoblast differentiation and bone matrix mineralization. Its ubiquitous presence is thought to prevent “soft” tissue calcification, whereas its degradation to Pi in bones and teeth by alkaline phosphatase (ALP) may facilitate crystal growth. While the inhibiting role of PPi on osteoblast differentiation and function is largely understood, less is known about its effects on osteoclast determination and activity. In this study, we investigated the role of PPi in bone resorption using calverial organ cultures ex vivo. We present an evidence that PPi stimulated calvarial bone resorption marked by calcium (Ca2+) release in the condition media (CM). We then examined PPi effects on osteoclast differentiation using mouse bone marrow-derived monocytes (BMMs). Our results revealed that PPi enhanced osteoclast differentiation ex vivo, marked by increased number and size of TRAP-stained mature osteoclasts. Moreover, PPi stimulated osteoclastogenesis in BMMs co-cultured with osteoblasts. These data supported the increased osteoclast activity in bone resorption using functional osteo-assays. The finding of PU.1-Egr-1 dependent up-regulation of c-FMS and RANK receptors in BMMs supported the enhanced pre-osteoclast commitment and differentiation. Moreover, osteoclast survival was enhanced by activation of MITF-BCL-2 pathway that was mediated by MAPK-ERK1/2 signaling. Last, our data showed that PPi up-regulated ANK; PPi transporter, during osteoclast differentiation through ERK1/2 phosphorylation whereas mutation of ANK inhibited osteoclastogenesis. Collectively, our data suggest that PPi promotes osteoclast differentiation, survival, and function through PU.1 up-regulation and MITF phosphorylation whereas ANK loss-of-function inhibited osteoclastogenesis.

scholarly journals GPR109A mediates the effects of hippuric acid on regulating osteoclastogenesis and bone resorption in mice

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Jin-Ran Chen ◽  
Haijun Zhao ◽  
Umesh D. Wankhade ◽  
Sree V. Chintapalli ◽  
Can Li ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Bone Resorption ◽  
Bone Mass ◽  
Hippuric Acid ◽  
Ex Vivo ◽  
Marrow Cell ◽  
Osteoclast Differentiation ◽  
Bone Homeostasis ◽  
Wild Type ◽  
Osteoclast Precursors

AbstractThe G protein-coupled receptor 109 A (GPR109A) is robustly expressed in osteoclastic precursor macrophages. Previous studies suggested that GPR109A mediates effects of diet-derived phenolic acids such as hippuric acid (HA) and 3-(3-hydroxyphenyl) propionic acid (3-3-PPA) on promoting bone formation. However, the role of GPR109A in metabolic bone homeostasis and osteoclast differentiation has not been investigated. Using densitometric, bone histologic and molecular signaling analytic methods, we uncovered that bone mass and strength were significantly higher in tibia and spine of standard rodent diet weaned 4-week-old and 6-month-old GPR109A gene deletion (GPR109A−/−) mice, compared to their wild type controls. Osteoclast numbers in bone and in ex vivo bone marrow cell cultures were significantly decreased in GPR109A−/− mice compared to wild type controls. In accordance with these data, CTX-1 in bone marrow plasma and gene expression of bone resorption markers (TNFα, TRAP, Cathepsin K) were significantly decreased in GPR109A−/− mice, while on the other hand, P1NP was increased in serum from both male and female GPR109A−/− mice compared to their respective controls. GPR109A deletion led to suppressed Wnt/β-catenin signaling in osteoclast precursors to inhibit osteoclast differentiation and activity. Indeed, HA and 3-3-PPA substantially inhibited RANKL-induced GPR109A expression and Wnt/β-catenin signaling in osteoclast precursors and osteoclast differentiation. Resultantly, HA significantly inhibited bone resorption and increased bone mass in wild type mice, but had no additional effects on bone in GPR109A−/− mice compared with their respective untreated control mice. These results suggest an important role for GPR109A during osteoclast differentiation and bone resorption mediating effects of HA and 3-3-PPA on inhibiting bone resorption during skeletal development.

Autocrine Regulation of Osteoclast Formation and Bone Resorption by IL-1α and TNFα

1999 ◽  
Vol 78 (10) ◽  
pp. 1617-1623 ◽  
Author(s):  
N. Tani-Ishii ◽  
A. Tsunoda ◽  
T. Teranaka ◽  
T. Umemoto
Keyword(s):  
Bone Resorption ◽  
Osteoclast Differentiation ◽  
Osteoclast Formation ◽  
Mouse Bone Marrow ◽  
Multinucleated Cells ◽  
Multinuclear Cells ◽  
And Control

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.

scholarly journals Anti-IFN-γ Antibody Promotes Osteoclastogenesis in Human Bone Marrow Monocyte-Derived Macrophages Co-Cultured with Tuberculosis-Activated Th1 Cells

2018 ◽  
Vol 49 (4) ◽  
pp. 1512-1522
Author(s):  
Jiezhong Deng ◽  
Dong Sun ◽  
Fei Luo ◽  
Qiang Zhang ◽  
Feifan Chen ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Bone Resorption ◽  
Osteoclast Differentiation ◽  
Osteoclast Formation ◽  
Th1 Cells ◽  
Actin Ring ◽  
Tnf Α ◽  
Ifn Γ ◽  
Trap Staining

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.

Adenosine Regulates Bone Metabolism Via A1, A2A and A2B Receptors in Bone Marrow Cells From Normal and Patients with Multiple Myeloma

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 4977-4977
Author(s):  
Wenjie He ◽  
Jeesun Park ◽  
Amitabha Mazumder ◽  
Bruce Cronstein
Keyword(s):  
Multiple Myeloma ◽  
Bone Marrow ◽  
Bone Resorption ◽  
Receptor Agonist ◽  
Osteoblast Differentiation ◽  
Osteoclast Differentiation ◽  
Activity Assay ◽  
Alizarin Red ◽  
Alp Activity ◽  
A2a Receptor

Abstract Abstract 4977 Background: Multiple myeloma is characterized by osteolytic bone lesions, wherein coupled bone remodeling is disrupted with increased osteoclast activation and decreased osteoblast differentiation. We have previously demonstrated that adenosine, acting via A2A receptors, diminishes human and murine osteoclast formation and others have reported that adenosine, acting at A2Breceptors, promotes osteoblast differentiation in murine osteoblast precursors and cell lines. In this study, we examined the effect of adenosine on osteoblast and osteoclast differentiation derived from multiple myeloma (MM) patients. Methods: Human bone marrow was collected from multiple myeloma patients. Bone marrow stromal cells (BMSCs) and bone marrow derived mononuclear (BMMs) cells were isolated and osteoblasts and osteoclastswere cultured, respectively. Adenosine A1 receptor agonist CHA and antagonist Rolofylline, A2A receptor agonist CGS and antagonist ZM, and A2b receptor agonist BAY and antagonist MRS 1754, A3receptor agonist IB-MECA and antagonist MRS 1191; and dipyridamole, a nucleoside transport inhibitor, were added to the culture media. Alkaline phosphatase (ALP) activity assay was used to quantitate the osteoblast differentiation. In vitro osteoblast calcification was determined by alizarin red staining. TRAP+ staining was used to examine the osteoclast differentiation and bone resorption assay was used to study the osteoclast activity. Results: We found that A1R blockade by rolofyllineand A2aR ligation by CGS21680 inhibited differentiation of both normal and MM BMMs into TRAP+ multinucleated cells (IC50= 1nM for A1R, IC50= 10μM for A2AR;p<0. 001, n=3 for both). The inhibition of osteoclast differentiation by Rolofylline was also seen in bone resorption assay (Pit formation assay). The A2A receptor antagonist completely reversed the effects of CGS21680 on osteoclast differentiation. Moreover, enhanced adenosine accumulation in the presence of dipyridamole (0. 5μM) and A2BR activation promoted the differentiation of BMSCs from myeloma patients into osteoblasts shown byArlizarin red staining and ALP activity assay (by 1. 8 ± 0. 41 and 1. 57 ± 0. 26 fold, respectively, p<0. 05, compared with osteogenic media only, n=3 for both). Conclusions: These results indicate that adenosine A2 receptors may be useful targets for the treatment and prevention of MM-induced bone disease. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Irisin directly stimulates osteoclastogenesis and bone resorption in vitro and in vivo

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Eben G Estell ◽  
Phuong T Le ◽  
Yosta Vegting ◽  
Hyeonwoo Kim ◽  
Christiane Wrann ◽  
...  
Keyword(s):  
Gene Expression ◽  
Bone Marrow ◽  
Bone Resorption ◽  
Osteoclast Differentiation ◽  
Neutralizing Antibody ◽  
Mouse Bone Marrow ◽  
Differential Gene

Irisin, a skeletal-muscle secreted myokine, facilitates muscle-bone crosstalk and skeletal remodeling in part by its action on osteoblasts and osteocytes. In this study, we investigated whether irisin directly regulates osteoclasts. In vitro, irisin (2–10 ng/mL) increased osteoclast differentiation in C57BL/6J mouse bone marrow progenitors; however, this increase was blocked by a neutralizing antibody to integrin αVβ5. Irisin also increased bone resorption on several substrates in situ. RNAseq revealed differential gene expression induced by irisin including upregulation of markers for osteoclast differentiation and resorption, as well as osteoblast-stimulating ‘clastokines’. Forced expression of the irisin precursor Fndc5 in transgenic C57BL/6J mice resulted in lower bone mass at three ages and greater in vitro osteoclastogenesis from Fndc5-transgenic bone marrow progenitors. This study demonstrates that irisin acts directly on osteoclast progenitors to increase differentiation and promote bone resorption, supporting the tenet that irisin not only stimulates bone remodeling but may also be an important counter-regulatory hormone.

scholarly journals Triptolide Inhibits Osteoclast Differentiation and Bone ResorptionIn Vitrovia Enhancing the Production of IL-10 and TGF-β1 by Regulatory T Cells

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Huihui Xu ◽  
Hongyan Zhao ◽  
Cheng Lu ◽  
Qi Qiu ◽  
Gui Wang ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Bone Marrow ◽  
Bone Resorption ◽  
Regulatory Mechanism ◽  
Osteoclast Differentiation ◽  
Bone Destruction ◽  
Mouse Bone Marrow ◽  
Potential Therapeutic Target ◽  
Therapeutic Mechanism ◽  
Tgf Β1

Triptolide, a purified component ofTripterygiumwilfordii Hook F, has been shown to have immunosuppressive and anti-inflammatory properties in rheumatoid arthritis (RA). Although triptolide has demonstrated that it could suppress bone destruction in collagen-induced mice, its therapeutic mechanism remains unclear. Many studies have investigated the effect of triptolide on Tregs and Tregs-related cytokine involved in RA. Additionally, previous studies have implied that Tregs inhibit osteoclast differentiation and bone resorption. Thus, in this study we aimed to explore the regulatory mechanism by which triptolide influences the Treg-mediated production of IL-10 and TGF-β1 to affect osteoclast differentiation and bone resorption. In cocultures system of Tregs and mouse bone marrow macrophages (BMMs), Tregs inhibited the differentiation of osteoclasts and reduced the resorbed areas significantly and the production of both IL-10 and TGF-β1 was upregulated. When the coculture systems were pretreated with triptolide, they produced higher levels of IL-10 and TGF-β1. Our data indicate that triptolide enhances the suppressive effects of Tregs on osteoclast differentiation and bone resorption by enhancing the secretion of IL-10 and TGF-β1. Tregs are most likely involved in the triptolide-mediated regulation of bone metabolism and may provide a potential therapeutic target for the treatment of inflammatory bone destruction.

scholarly journals HDAC9 Inhibits Osteoclastogenesis via Mutual Suppression of PPARγ/RANKL Signaling

2015 ◽  
Vol 29 (5) ◽  
pp. 730-738 ◽  
Author(s):  
Zixue Jin ◽  
Wei Wei ◽  
HoangDinh Huynh ◽  
Yihong Wan
Keyword(s):  
Bone Marrow ◽  
Bone Resorption ◽  
Hormone Receptors ◽  
Ex Vivo ◽  
Osteoclast Differentiation ◽  
Nuclear Factor Κb ◽  
Peroxisome Proliferator ◽  
Nuclear Factor ◽  
Peroxisome Proliferator Activated Receptor ◽  
Regulatory Loop

Abstract Recent studies suggest that the class II histone deacetylase (HDAC)9 plays important roles in physiology such as metabolism and immunity. Here, we report that HDAC9 also controls bone turnover by suppressing osteoclast differentiation and bone resorption. HDAC9 expression is down-regulated during osteoclastogenesis. Ex vivo osteoclast differentiation is accelerated by HDAC9 deletion but diminished by HDAC9 overexpression. HDAC9 knockout mice exhibit elevated bone resorption and lower bone mass. Bone marrow transplantation reveal that the osteoclastogenic defects are intrinsic to the hematopoietic lineage, because the excessive bone resorption phenotype can be conferred in wild-type (WT) mice receiving HDAC9-null bone marrow, and rescued in HDAC9-null mice receiving WT bone marrow. Mechanistically, HDAC9 forms a negative regulatory loop with peroxisome proliferator-activated receptor gamma (PPARg) and receptor activator of nuclear factor kappa-B ligand (RANKL) signaling. On one hand, PPARγ and nuclear factor κB suppress HDAC9 expression, on the other hand, HDAC9 inhibits PPARγ activity in synergy with silencing mediator of retinoic acid and thyroid hormone receptors (SMRT)/NCoR corepressors. These findings identify HDAC9 as a novel, important and physiologically relevant modulator of bone remodeling and skeletal homeostasis.

scholarly journals Identifying genes that regulate bone remodeling as potential therapeutic targets

2005 ◽  
Vol 201 (6) ◽  
pp. 841-843 ◽  
Author(s):  
Stephen M. Krane
Keyword(s):  
Bone Resorption ◽  
Bone Loss ◽  
Bone Remodeling ◽  
Osteoblast Differentiation ◽  
Osteoclast Differentiation ◽  
Protein Signaling ◽  
Coupled Process ◽  
Systemic Factors ◽  
And Function ◽  
Deficient Mice

Bone remodeling, a coupled process involving bone resorption and formation, is initiated by mechanical signals and is controlled by local and systemic factors that regulate osteoblast and osteoclast differentiation and function. An excess of resorption over formation leads to the bone loss and increased propensity to fracture that is characteristic of osteoporosis. A newly described inhibitor of osteoblast differentiation, Ciz, interferes with bone morphogenic protein signaling. As a consequence, Ciz-deficient mice develop increased bone mass.

scholarly journals Unexpected Role of Matrix Gla Protein in Osteoclasts: Inhibiting Osteoclast Differentiation and Bone Resorption

2019 ◽  
Vol 39 (12) ◽  
Author(s):  
Yan Zhang ◽  
Liting Zhao ◽  
Naining Wang ◽  
Jing Li ◽  
Fang He ◽  
...  
Keyword(s):  
Bone Resorption ◽  
Nuclear Translocation ◽  
Current Knowledge ◽  
Bone Matrix ◽  
Osteoclast Differentiation ◽  
Matrix Gla Protein ◽  
Activated T Cells ◽  
And Function

ABSTRACT Matrix Gla protein (MGP) is an extracellular protein responsible for inhibiting mineralization. MGP inhibits osteoblast mineralization and bone formation by regulating the deposition of bone matrix. However, Mgp–/– mice display an osteopenic phenotype. To explain this contradiction, we investigated the role of MGP in osteoclastogenesis, the other side of bone remodeling. We found that MGP expression is markedly increased by osteoclastic commitment. Osteoclast differentiation and bone resorption are accelerated by MGP depletion while suppressed by MGP overexpression. The in vivo results confirmed its inhibitory role in osteoclastogenesis by the administration of Cre-dependent FLEX-On recombinant MGP-AAV to LysM Cre mice. Furthermore, we found that the expression and nuclear translocation of nuclear factor of activated T cells, cytoplasmic 1 (NFATc1), are under the control of MGP. MGP loss results in elevation of intracellular Ca2+ flux. Vitronectin-induced activation of Src/Rac1 is magnified in the absence of MGP but reduced when MGP is overexpressed. Inhibition of Src activation or NFATc1 nuclear import rescues the increased osteoclastogenesis induced by MGP deficiency. These observations (i) establish, for the first time to our knowledge, that MGP plays an essential role in osteoclast differentiation and function, (ii) enrich the current knowledge of MGP function, and (iii) indicate the potential of MGP as a therapeutic target for low-bone-mass disorders.

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