scholarly journals Ormeloxifene inhibits osteoclast differentiation in parallel to downregulating RANKL-induced ROS generation and suppressing the activation of ERK and JNK in murine RAW264.7 cells

2012 ◽  
Vol 48 (3) ◽  
pp. 261-270 ◽  
Author(s):  
Geetika Kharkwal ◽  
Vishal Chandra ◽  
Iram Fatima ◽  
Anila Dwivedi
Keyword(s):  
Transcription Factors ◽  
Mechanism Of Action ◽  
Transcriptional Activation ◽  
Osteoclast Differentiation ◽  
Osteoclast Formation ◽  
Raw264.7 Cells ◽  
Ros Generation ◽  
Dependent Manner ◽  
Murine Macrophage ◽  
Essential Components

Ormeloxifene (Orm), a triphenylethylene compound, has been established as a selective estrogen receptor modulator (SERM) that suppresses the ovariectomy-induced bone resorption in rats. However, the precise mechanism underlying the bone-preserving action of Orm remains unclear. In this study, we evaluated the effect of Orm on osteoclast formation induced by receptor activator of nuclear factor κB ligand (RANKL) in the murine macrophage cell line RAW264.7. We also explored the mechanism of action of Orm by studying the RANKL-induced signaling pathways required for osteoclast differentiation. We found that Orm inhibited osteoclast formation from murine macrophage RAW264.7 cells induced by RANKL in a dose-dependent manner. Orm was able to abolish RANKL-induced reactive oxygen species (ROS) elevation and inhibited the transcriptional activation of two key RANKL-induced transcription factors namely activator protein-1 (AP-1) and NF-κB through mechanisms involving MAPKs. Activation of two MAPKs, i.e. ERK (MAPK1) and JNK (MAPK8), was alleviated by Orm effectively, which subsequently affected the activation of c-Jun and c-Fos, which are the essential components of the AP-1 transcription complex. Taken together, our results demonstrate that Orm potentially inhibits osteoclastogenesis by inhibiting ROS generation and thereby suppressing the activation of ERK1/2 (MAPK3/MAPK1) and JNK (MAPK8) and transcription factors (NF-κB and AP-1), which subsequently affect the regulation of osteoclastogenesis. These results provide a possible mechanism of action of Orm in regulating osteoclastogenesis, thereby supporting the beneficial bone-protective effects of this compound.

scholarly journals Activating Signal Cointegrator 2 Belongs to a Novel Steady-State Complex That Contains a Subset of Trithorax Group Proteins

2003 ◽  
Vol 23 (1) ◽  
pp. 140-149 ◽  
Author(s):  
Young-Hwa Goo ◽  
Young Chang Sohn ◽  
Dae-Hwan Kim ◽  
Seung-Whan Kim ◽  
Min-Jung Kang ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Steady State ◽  
Nuclear Receptors ◽  
Transcriptional Activation ◽  
Retinoic Acid Receptor ◽  
Dependent Manner ◽  
Trithorax Group ◽  
Trithorax Group Proteins

ABSTRACT Many transcription coactivators interact with nuclear receptors in a ligand- and C-terminal transactivation function (AF2)-dependent manner. These include activating signal cointegrator 2 (ASC-2), a recently isolated transcriptional coactivator molecule, which is amplified in human cancers and stimulates transactivation by nuclear receptors and numerous other transcription factors. In this report, we show that ASC-2 belongs to a steady-state complex of approximately 2 MDa (ASC-2 complex [ASCOM]) in HeLa nuclei. ASCOM contains retinoblastoma-binding protein RBQ-3, α/β-tubulins, and trithorax group proteins ALR-1, ALR-2, HALR, and ASH2. In particular, ALR-1/2 and HALR contain a highly conserved 130- to 140-amino-acid motif termed the SET domain, which was recently implicated in histone H3 lysine-specific methylation activities. Indeed, recombinant ALR-1, HALR, and immunopurified ASCOM exhibit very weak but specific H3-lysine 4 methylation activities in vitro, and transactivation by retinoic acid receptor appears to involve ligand-dependent recruitment of ASCOM and subsequent transient H3-lysine 4 methylation of the promoter region in vivo. Thus, ASCOM may represent a distinct coactivator complex of nuclear receptors. Further characterization of ASCOM will lead to a better understanding of how nuclear receptors and other transcription factors mediate transcriptional activation.

scholarly journals Piceatannol attenuates RANKL-induced osteoclast differentiation and bone resorption by suppressing MAPK, NF-κB and AKT signalling pathways and promotes Caspase3-mediated apoptosis of mature osteoclasts

2019 ◽  
Vol 6 (6) ◽  
pp. 190360 ◽  
Author(s):  
Liuliu Yan ◽  
Lulu Lu ◽  
Fangbin Hu ◽  
Dattatrya Shetti ◽  
Kun Wei
Keyword(s):  
Bone Resorption ◽  
Osteoclast Differentiation ◽  
Giant Cells ◽  
Inhibitory Effect ◽  
Osteoclast Formation ◽  
Bone Diseases ◽  
Signalling Pathways ◽  
Dependent Manner ◽  
Underlying Mechanisms ◽  
And Function

Osteoclasts are multinuclear giant cells that have unique ability to degrade bone. The search for new medicines that modulate the formation and function of osteoclasts is a potential approach for treating osteoclast-related bone diseases. Piceatannol (PIC) is a natural organic polyphenolic stilbene compound found in diverse plants with a strong antioxidant and anti-inflammatory effect. However, the effect of PIC on bone health has not been scrutinized systematically. In this study, we used RAW264.7, an osteoclast lineage of cells of murine macrophages, to investigate the effects and the underlying mechanisms of PIC on osteoclasts. Here, we demonstrated that PIC treatment ranging from 0 to 40 µM strongly inhibited osteoclast formation and bone resorption in a dose-dependent manner. Furthermore, the inhibitory effect of PIC was accompanied by the decrease of osteoclast-specific genes. At the molecular level, PIC suppressed the phosphorylation of c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinase (ERK1/2), NF-κB p65, IκBα and AKT. Besides, PIC promoted the apoptosis of mature osteoclasts by inducing caspase-3 expression. In conclusion, our results suggested that PIC inhibited RANKL-induced osteoclastogenesis and bone resorption by suppressing MAPK, NF-κB and AKT signalling pathways and promoted caspase3-mediated apoptosis of mature osteoclasts, which might contribute to the treatment of bone diseases characterized by excessive bone resorption.

scholarly journals Signal regulatory protein α1 is involved in the inhibitory effect of glucocorticoid receptor on the proliferation of murine macrophage RAW264.7 cell and mouse peritoneal macrophage

2008 ◽  
Vol 41 (5) ◽  
pp. 393-403 ◽  
Author(s):  
Xiaohui Wang ◽  
Yidong Li ◽  
Xiaoyan Zhu ◽  
Yan Wang ◽  
Fei Diao ◽  
...  
Keyword(s):  
Rna Interference ◽  
Peritoneal Macrophage ◽  
Inflammatory Responses ◽  
Regulatory Protein ◽  
Mouse Peritoneal Macrophage ◽  
Raw264.7 Cells ◽  
Dependent Manner ◽  
Proliferation Inhibition ◽  
Murine Macrophage ◽  
Concentration Dependent Manner

Glucocorticoid (GC) effectively suppresses immune and inflammatory responses and inhibits the growth of several types of cells, but the role of GC and its receptor on macrophage proliferation is unclear. In our previous work, we found RAW-GR(−) cells (murine macrophage RAW264.7 cells stably transfected with GR-siRNA expression vector by RNA interference) grew faster by about twofold. In this study, we further explored the role and mechanisms of GC/GR on the proliferation of macrophage. We found that the growth of RAW264.7 cells was inhibited by dexamethasone (Dex) in a concentration-dependent manner. The mRNA and protein levels of signal regulatory protein α1 (SIRPA) were induced by GC/GR in RAW264.7 cells and SIRPA expression was decreased remarkably in RAW-GR(−) cells. Overexpression of SIRPA negatively regulated the proliferation of RAW-GR(−) cells, and inhibition of SIRPA expression by a small from RNA interference attenuated Dex-induced proliferation inhibition in RAW264.7 cells. The proliferation inhibition of GC/GR was also found in mouse peritoneal macrophage, which was associated with the increase in SIRPA induced by GC/GR as well. In addition, elevation of the expression of CDK2, cyclinD1, and cyclinB1, but not phosphorylated ERK1/2 and p38, was found in RAW-GR(−) cells. In conclusion, we provided the novel evidences that GC/GR inhibited the growth of RAW264.7 cells and mouse peritoneal macrophage, and the antiproliferative effect of GC/GR on these cells was at least in part a result from GC/GR-induced SIRPA expression. Up-regulation of CDK2, cyclinD1, and cyclinB1 was also related to the increased proliferation of RAW-GR(−) cells.

scholarly journals Stepwise Recruitment of Components of the Preinitiation Complex by Upstream Activators In Vivo

1998 ◽  
Vol 18 (5) ◽  
pp. 2876-2883 ◽  
Author(s):  
Song He ◽  
Steven Jay Weintraub
Keyword(s):  
Transcription Factors ◽  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Mechanism Of Action ◽  
Transcriptional Activation ◽  
Tata Binding Protein ◽  
Preinitiation Complex ◽  
Functional Assays ◽  
Rna Polymerase Ii Holoenzyme

ABSTRACT Recently, it was found that if either the TATA binding protein or RNA polymerase II holoenzyme is artificially tethered to a promoter, transcription is activated. This finding provided presumptive evidence that upstream activating proteins function by recruiting components of the preinitiation complex (PIC) to the promoter. To date, however, there have been no studies demonstrating that upstream factors actually recruit components of the PIC to the promoter in vivo. Therefore, we have studied the mechanism of action of two disparate transactivating domains. We present a series of in vivo functional assays that demonstrate that each of these proteins targets different components of the PIC for recruitment. We show that, by targeting different components of the PIC for recruitment, these activating domains can cooperate with each other to activate transcription synergistically and that, even within one protein, two different activating subdomains can activate transcription synergistically by cooperating to recruit different components of the PIC. Finally, considering our work together with previous studies, we propose that certain transcription factors both recruit components of the PIC and facilitate steps in transcriptional activation that occur subsequent to recruitment.

scholarly journals Jun Dimerization Protein 2 (JDP2), a Member of the AP-1 Family of Transcription Factor, Mediates Osteoclast Differentiation Induced by RANKL

2003 ◽  
Vol 197 (8) ◽  
pp. 1029-1035 ◽  
Author(s):  
Reimi Kawaida ◽  
Toshiaki Ohtsuka ◽  
Junichi Okutsu ◽  
Tohru Takahashi ◽  
Yuho Kadono ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Bone Marrow Cells ◽  
Osteoclast Differentiation ◽  
Osteoclast Formation ◽  
Raw264.7 Cells ◽  
Tartrate Resistant Acid Phosphatase ◽  
Gene Promoters ◽  
Primary Bone ◽  
Primary Bone Marrow ◽  
Marrow Cells

Osteoclasts are multinucleated cells that resorb bones, and are derived from hematopoietic cells of the monocyte/macrophage lineage. The receptor activator of NF-κB ligand (RANKL, also called ODF/TRANCE/OPGL) stimulates both osteoclast differentiation from osteoclast progenitors and activation of mature osteoclasts. To identify genes responsible for osteoclast differentiation, we used a molecular indexing technique. Here, we report a clone of one of these genes whose transcription is induced by soluble RANKL (sRANKL) in both the RAW264.7 cells of the mouse macrophage cell line and the mouse primary bone marrow cells. The predicted protein was found to be a mouse homologue of Jun dimerization protein 2 (JDP2), a member of the AP-1 family of transcription factors, containing a basic region-leucine zipper motif. Transient transfection experiments revealed that overexpression of JDP2 leads to activation of both tartrate-resistant acid phosphatase (TRAP) and cathepsin K gene promoters in RAW264.7 cells. Infection of mouse primary bone marrow cells with retroviruses expressing JDP2-facilitated sRANKL-mediated formation of TRAP-positive multinuclear osteoclasts. Importantly, antisense oligonucleotide to JDP2 strongly suppressed sRANKL-induced osteoclast formation of RAW264.7 cells. Our findings suggest that JDP2 may play an important role in the RANK-mediated signal transduction system, especially in osteoclast differentiation.

scholarly journals Butyrate Inhibits Osteoclast Activity In Vitro and Regulates Systemic Inflammation and Bone Healing in a Murine Osteotomy Model Compared to Antibiotic-Treated Mice

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Alexandra Wallimann ◽  
Walker Magrath ◽  
Brenna Pugliese ◽  
Nino Stocker ◽  
Patrick Westermann ◽  
...  
Keyword(s):  
Fracture Healing ◽  
Systemic Inflammation ◽  
Bone Healing ◽  
Bone Turnover Marker ◽  
Osteoclast Differentiation ◽  
Short Chain Fatty Acids ◽  
Osteoclast Formation ◽  
Dependent Manner

Short-chain fatty acids (SCFAs) produced by the gut microbiota have previously been demonstrated to play a role in numerous chronic inflammatory diseases and to be key mediators in the gut-bone signaling axis. However, the role of SCFAs in bone fracture healing and its impact on systemic inflammation during the regeneration process has not been extensively investigated yet. The aim of this study was to first determine the effects of the SCFA butyrate on key cells involved in fracture healing in vitro, namely, osteoclasts and mesenchymal stromal cells (MSCs), and second, to assess if butyrate supplementation or antibiotic therapy impacts bone healing, systemic immune status, and inflammation levels in a murine osteotomy model. Butyrate significantly reduced osteoclast formation and resorption activity in a dose-dependent manner and displayed a trend for increased calcium deposits in MSC cultures. Numerous genes associated with osteoclast differentiation were differentially expressed in osteoclast precursor cells upon butyrate exposure. In vivo, antibiotic-treated mice showed reduced SCFA levels in the cecum, as well as a distinct gut microbiome composition. Furthermore, circulating proinflammatory TNFα, IL-17a, and IL-17f levels, and bone preserving osteoprotegerin (OPG), were increased in antibiotic-treated mice compared to controls. Antibiotic-treated mice also displayed a trend towards delayed bone healing as revealed by reduced mineral apposition at the defect site and higher circulating levels of the bone turnover marker PINP. Butyrate supplementation resulted in a lower abundance of monocyte/macrophages in the bone marrow, as well as reduced circulating proinflammatory IL-6 levels compared to antibiotic- and control-treated mice. In conclusion, this study supports our hypothesis that SCFAs, in particular butyrate, are important contributors to successful bone healing by modulating key cells involved in fracture healing as well as systemic inflammation and immune responses.

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 BCPA {N,N′-1,4-Butanediylbis[3-(2-chlorophenyl)acrylamide]} Inhibits Osteoclast Differentiation through Increased Retention of Peptidyl-Prolyl cis-trans Isomerase Never in Mitosis A-Interacting 1

2018 ◽  
Vol 19 (11) ◽  
pp. 3436 ◽  
Author(s):  
Eugene Cho ◽  
Jin-Kyung Lee ◽  
Jee-Young Lee ◽  
Zhihao Chen ◽  
Sun-Hee Ahn ◽  
...  
Keyword(s):  
Mononuclear Cells ◽  
Transmembrane Protein ◽  
Osteoclast Differentiation ◽  
Osteoclast Formation ◽  
Tartrate Resistant Acid Phosphatase ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Nuclear Factor ◽  
Activated T Cells ◽  
And Function

Osteoporosis is caused by an imbalance of osteoclast and osteoblast activities and it is characterized by enhanced osteoclast formation and function. Peptidyl-prolyl cis-trans isomerase never in mitosis A (NIMA)-interacting 1 (Pin1) is a key mediator of osteoclast cell-cell fusion via suppression of the dendritic cell-specific transmembrane protein (DC-STAMP). We found that N,N′-1,4-butanediylbis[3-(2-chlorophenyl)acrylamide] (BCPA) inhibited receptor activator of nuclear factor kappa-B ligand (RANKL)-induced osteoclastogenesis in a dose-dependent manner without cytotoxicity. In addition, BCPA attenuated the reduction of Pin1 protein during osteoclast differentiation without changing Pin1 mRNA levels. BCPA repressed the expression of osteoclast-related genes, such as DC-STAMP and osteoclast-associated receptor (OSCAR), without altering the mRNA expression of nuclear factor of activated T cells (NFATc1) and cellular oncogene fos (c-Fos). Furthermore, Tartrate-resistant acid phosphatase (TRAP)-positive mononuclear cells were significantly decreased by BCPA treatment compared to treatment with the Pin1 inhibitor juglone. These data suggest that BCPA can inhibit osteoclastogenesis by regulating the expression of the DC-STAMP osteoclast fusion protein by attenuating Pin1 reduction. Therefore, BCPA may be used to treat osteoporosis.

MafB negatively regulates RANKL-mediated osteoclast differentiation

Blood ◽  
2006 ◽  
Vol 109 (8) ◽  
pp. 3253-3259 ◽  
Author(s):  
Kabsun Kim ◽  
Jung Ha Kim ◽  
Junwon Lee ◽  
Hye Mi Jin ◽  
Hyun Kook ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Transcription Factors ◽  
Phagocytic Activity ◽  
Osteoclast Differentiation ◽  
Nuclear Factor Κb ◽  
Osteoclast Formation ◽  
Nuclear Factor ◽  
Binding Ability ◽  
Receptor Activator ◽  
Macrophage Lineage

Abstract Receptor activator of nuclear factor κB ligand (RANKL) induces osteoclast formation from hematopoietic cells via regulation of various transcription factors. Here, we show that MafB negatively regulates RANKL-induced osteoclast differentiation. Expression levels of MafB are significantly reduced by RANKL during osteoclastogenesis. Overexpression of MafB in bone marrow-derived monocyte/macrophage lineage cells (BMMs) inhibits the formation of TRAP+ multinuclear osteoclasts, but phagocytic activity of BMMs is retained. Furthermore, overexpression of MafB in BMMs attenuates the gene induction of NFATc1 and osteoclast-associated receptor (OSCAR) during RANKL-mediated osteoclastogenesis. In addition, MafB proteins interfere with the DNA-binding ability of c-Fos, Mitf, and NFATc1, inhibiting their transactivation of NFATc1 and OSCAR. Furthermore, reduced expression of MafB by RNAi enhances osteoclastogenesis and increases expression of NFATc1 and OSCAR. Taken together, our results suggest that MafB can act as an important modulator of RANKL-mediated osteoclastogenesis.

scholarly journals 3-(4-Methoxyl)-1-(2-(4-coumarin)prop)-2-en-1-one inhibits the differentiation of osteoclasts

2020 ◽  
Author(s):  
Yingxiao Fu ◽  
Yihui Wang ◽  
Dequn Niu ◽  
Baoding Tang ◽  
Yingji Mao ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Cell Viability ◽  
Mononuclear Cells ◽  
Osteoclast Differentiation ◽  
The Body ◽  
Raw264.7 Cells ◽  
Tartrate Resistant Acid Phosphatase ◽  
Filamentous Actin ◽  
Change Level ◽  
Actin Rings

Abstract Background: Osteoclasts are large terminal-differentiated cells with multiple nuclei and are the only cells with bone resorption activity in the body. The abnormal migration and differentiation of osteoclasts may accelerate bone absorption, a crucial process in the occurrence and development of osteoporosis. Regulating the differentiation and activation of osteoclasts is a breakthrough point for the prevention and treatment of osteoporosis. Coumarin derivative of 3-(4-methoxyl)-1-(2-(4-coumarin) prop)-2-en-1-one (MCPEO) was selected in this study. We aimed to investigate the effects of (MCPEO) on osteoclast differentiation. Methods: Bone marrow mononuclear cells (BM-MNCs) were collected from 6-week-old ICR mice and inoculated in vitro. BM-MNC and RAW264.7 cells were induced by the receptor activator of nuclear factor κ B ligand (RANKL) to differentiate them into osteoclasts. The cells were then added with 0.01, 0.05, 0.1, 0.5, and 1 μM MCPEO. The cell viability of differentiated osteoclasts was analyzed by methylthiazolyldiphenyl-tetrazolium bromide assay. The differentiated osteoclasts were detected by tartrate-resistant acid phosphatase (TRAP) staining. Miuse osteoclast activation was investigated by absorptive activity analysis. Filamentous actin (F-actin) staining was employed to identify the formation of F-actin rings in the differentiated mouse osteoclasts. The change level of critical transcription factors related to osteoclast differentiation was determined by Western blot analysis. Results: Data show that MCPEO affected the cell viability of differentiated osteoclasts, inhibited the formation of TRAP-positive polynuclear cells, and decreased the absorption activity and the formation of F-actin rings in the differentiated osteoclasts. Furthermore, MCPEO influenced the change level of crucial transcription factors related to osteoclast differentiation. Conclusions: MCPEO inhibited the differentiation of RANKL-induced BM-MNC and RAW264.7 cells into osteoclasts.

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