Inhibition of bone resorption in vitro and prevention of ovariectomy-induced bone loss in vivo by flurbiprofen nitroxybutylester (HCT1026)

Loss of ovarian function is closely related to estrogen (E2) deficiency, which is responsible for increased osteoclast (OC) differentiation and activity. We aimed to investigate the action mechanism of E2 to decrease bone resorption in OCs to protect from ovariectomy (OVX)-induced bone loss in mice. In vivo, tartrate-resistant acid phosphatase (TRAP) staining in femur and serum carboxy-terminal collagen crosslinks-1 (CTX-1) were analyzed upon E2 injection after OVX in mice. In vitro, OCs were analyzed by TRAP staining, actin ring formation, carboxymethylation, determination of reactive oxygen species (ROS) level, and immunoprecipitation coupled with Western blot. In vivo and in vitro, E2 decreased OC size more dramatically than OC number and Methyl-piperidino-pyrazole hydrate dihydrochloride (MPPD), an estrogen receptor alpha (ERα) antagonist, augmented the OC size. ERα was found in plasma membranes and E2/ERα signaling affected receptor activator of nuclear factor κB ligand (RANKL)-induced actin ring formation by rapidly decreasing a proto-oncogene tyrosine-protein kinase, cellular sarcoma (c-Src) (Y416) phosphorylation in OCs. E2 exposure decreased physical interactions between NADPH oxidase 1 (NOX1) and the oxidized form of c-Src homology 2 (SH2)-containing protein tyrosine phosphatase 2 (SHP2), leading to higher levels of reduced SHP2. ERα formed a complex with the reduced form of SHP2 and c-Src to decrease c-Src activation upon E2 exposure, which blocked a signal for actin ring formation by decreased Vav guanine nucleotide exchange factor 3 (Vav3) (p–Y) and Ras-related C3 botulinum toxin substrate 1 (Rac1) (GTP) activation in OCs. E2/ERα signals consistently inhibited bone resorption in vitro. In conclusion, our study suggests that E2-binding to ERα forms a complex with SHP2/c-Src to attenuate c-Src activation that was induced upon RANKL stimulation in a non-genomic manner, resulting in an impaired actin ring formation and reducing bone resorption.

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Artesunate inhibits RANKL-induced osteoclastogenesis and bone resorption in vitro and prevents LPS-induced bone loss in vivo

Journal of Cellular Physiology ◽

10.1002/jcp.25907 ◽

2017 ◽

Vol 233 (1) ◽

pp. 476-485 ◽

Cited By ~ 21

Author(s):

Cheng-Ming Wei ◽

Qian Liu ◽

Fang-Ming Song ◽

Xi-Xi Lin ◽

Yi-Ji Su ◽

...

Keyword(s):

Bone Resorption ◽

Bone Loss

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Pristimerin Inhibits Osteoclast Differentiation and Bone Resorption in vitro and Prevents Ovariectomy-Induced Bone Loss in vivo

Drug Design Development and Therapy ◽

10.2147/dddt.s275128 ◽

2020 ◽

Vol Volume 14 ◽

pp. 4189-4203

Author(s):

Peng Sun ◽

Qichang Yang ◽

Yanben Wang ◽

Jiaxuan Peng ◽

Kangxian Zhao ◽

...

Keyword(s):

Bone Resorption ◽

Bone Loss ◽

Osteoclast Differentiation

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The Role of IL-1βin the Bone Loss during Rheumatic Diseases

Mediators of Inflammation ◽

10.1155/2015/782382 ◽

2015 ◽

Vol 2015 ◽

pp. 1-10 ◽

Cited By ~ 63

Author(s):

Piero Ruscitti ◽

Paola Cipriani ◽

Francesco Carubbi ◽

Vasiliki Liakouli ◽

Francesca Zazzeroni ◽

...

Keyword(s):

Bone Resorption ◽

Bone Loss ◽

Rheumatic Diseases ◽

Nuclear Factor Kappa B ◽

Inflammatory Diseases ◽

Receptor Activator ◽

Main Factor

Several inflammatory diseases have been associated with increased bone resorption and fracture rates and different studies supported the relation between inflammatory cytokines and osteoclast activity. The main factor required for osteoclast activation is the stimulation by receptor activator of nuclear factor kappa-B ligand (RANKL) expressed on osteoblasts. In this context, interleukin- (IL-) 1β, one of the most powerful proinflammatory cytokines, is a strong stimulator of in vitro and in vivo bone resorption via upregulation of RANKL that stimulates the osteoclastogenesis. The resulting effects lead to an imbalance in bone metabolism favouring bone resorption and osteoporosis. In this paper, we review the available literature on the role of IL-1βin the pathogenesis of bone loss. Furthermore, we analysed the role of IL-1βin bone resorption during rheumatic diseases and, when available, we reported the efficacy of anti-IL-1βtherapy in this field.

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Structural Dissection andIn VivoEffectiveness of a Peptide Inhibitor ofPorphyromonas gingivalisAdherence toStreptococcus gordonii

Infection and Immunity ◽

10.1128/iai.00361-10 ◽

2010 ◽

Vol 79 (1) ◽

pp. 67-74 ◽

Cited By ~ 73

Author(s):

Carlo Amorin Daep ◽

Elizabeth A. Novak ◽

Richard J. Lamont ◽

Donald R. Demuth

Keyword(s):

Bone Resorption ◽

Bone Loss ◽

Alveolar Bone ◽

Alveolar Bone Loss ◽

Peptide Inhibitor ◽

Dental Biofilm ◽

Streptococcal Antigen ◽

Α Helix

ABSTRACTThe interaction of the minor fimbrial antigen (Mfa) with streptococcal antigen I/II (e.g., SspB) facilitates colonization of the dental biofilm byPorphyromonas gingivalis.We previously showed that a 27-mer peptide derived from SspB (designated BAR) resembles the nuclear receptor (NR) box protein-protein interacting domain and potently inhibits this interactionin vitro. Here, we show that the EXXP motif upstream of the NR core α-helix contributes to the Mfa-SspB interaction and that BAR reducesP. gingivaliscolonization and alveolar bone lossin vivoin a murine model of periodontitis. Substitution of Gln for Pro1171or Glu1168increased the α-helicity of BAR and reduced its inhibitory activityin vitroby 10-fold and 2-fold, respectively. To determine if BAR preventsP. gingivalisinfectionin vivo, mice were first infected withStreptococcus gordoniiand then challenged withP. gingivalisin the absence and presence of BAR. Animals that were infected with either 109CFU ofS. gordoniiDL-1 or 107CFU ofP. gingivalis33277 did not show a statistically significant increase in alveolar bone resorption over sham-infected controls. However, infection with 109CFU ofS. gordoniifollowed by 107CFU ofP. gingivalisinduced significantly greater bone loss (P< 0.01) than sham infection or infection of mice with either organism alone.S. gordonii-infected mice that were subsequently challenged with 107CFU ofP. gingivalisin the presence of BAR exhibited levels of bone resorption similar to those of sham-infected animals. Together, these results indicate that both EXXP and the NR box are important for the Mfa-SspB interaction and that BAR peptide represents a potential therapeutic that may limit colonization of the oral cavity byP. gingivalis.

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Engineering of L-Plastin Peptide-Loaded Biodegradable Nanoparticles for Sustained Delivery and Suppression of Osteoclast Function In Vitro

International Journal of Cell Biology ◽

10.1155/2019/6943986 ◽

2019 ◽

Vol 2019 ◽

pp. 1-13 ◽

Cited By ~ 4

Author(s):

Sunipa Majumdar ◽

Aniket S. Wadajkar ◽

Hanan Aljohani ◽

Mark A. Reynolds ◽

Anthony J. Kim ◽

...

Keyword(s):

Bone Resorption ◽

Bone Loss ◽

Sustained Release ◽

Double Emulsion ◽

Small Molecular Weight ◽

Rhodamine Phalloidin ◽

Amino Terminal ◽

Osteoclast Function

We have recently demonstrated that a small molecular weight amino-terminal peptide of L-plastin (10 amino acids; “MARGSVSDEE”) suppressed the phosphorylation of endogenous L-plastin. Therefore, the formation of nascent sealing zones (NSZs) and bone resorption are reduced. The aim of this study was to develop a biodegradable and biocompatible PLGA nanocarrier that could be loaded with the L-plastin peptide of interest and determine the efficacy in vitro in osteoclast cultures. L-plastin MARGSVSDEE (P1) and scrambled control (P3) peptide-loaded PLGA-PEG nanoparticles (NP1 and NP3, respectively) were synthesized by double emulsion technique. The biological effect of nanoparticles on osteoclasts was evaluated by immunoprecipitation, immunoblotting, rhodamine-phalloidin staining of actin filaments, and pit forming assays. Physical characterization of well-dispersed NP1 and NP3 demonstrated ~130-150 nm size, < 0.07 polydispersity index, ~-3 mV ζ-potential, and a sustained release of the peptide for three weeks. Biological characterization in osteoclast cultures demonstrated the following: NP1 significantly reduced (a) endogenous L-plastin phosphorylation; (b) formation of NSZs and sealing rings; (c) resorption. However, the assembly of podosomes which are critical for cell adhesion was not affected. L-plastin peptide-loaded PLGA-PEG nanocarriers have promising potential for the treatment of diseases associated with bone loss. Future studies will use this sustained release of peptide strategy to systematically suppress osteoclast bone resorption activity in vivo in mouse models demonstrating bone loss.

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Osteoblast-osteoclast co-culture amplifies inhibitory effects of FG-4592 on osteoclast formation and reduces bone resorption activity

10.1101/863498 ◽

2019 ◽

Author(s):

Philippa A Hulley ◽

Ioanna Papadimitriou-Olivgeri ◽

Helen J Knowles

Keyword(s):

Bone Resorption ◽

Bone Loss ◽

Bone Formation ◽

Enzyme Inhibitors ◽

Enzyme Inhibitor ◽

Osteoclast Formation ◽

Potential Contribution ◽

Non Union

AbstractThe link between bone and blood vessels is regulated by hypoxia and the hypoxia-inducible transcription factor, HIF, which drives both osteogenesis and angiogenesis. The recent clinical approval of PHD enzyme inhibitors, which stabilise HIF protein, introduces the potential for a new clinical strategy to treat osteolytic conditions such as osteoporosis, osteonecrosis and skeletal fracture and non-union. However, bone-resorbing osteoclasts also play a central role in bone remodelling and pathological osteolysis and HIF promotes osteoclast activation and bone loss in vitro. It is therefore likely that the final outcome of PHD enzyme inhibition in vivo would be mediated by a balance between increased bone formation and increased bone resorption. It is essential that we improve our understanding of the effects of HIF on osteoclast formation and function, and consider the potential contribution of inhibitory interactions with other musculoskeletal cells.The PHD enzyme inhibitor FG-4592 stabilised HIF protein and stimulated osteoclast-mediated bone resorption, but inhibited differentiation of human CD14+ monocytes into osteoclasts. Formation of osteoclasts in a more physiologically relevant 3D collagen gel did not affect the sensitivity of osteoclastogenesis to FG-4592, but increased sensitivity to reduced concentrations of RANKL. Co-culture with osteoblasts amplified inhibition of osteoclastogenesis by FG-4592, whether the osteoblasts were proliferating, differentiating or in the presence of exogenous M-CSF and RANKL. Osteoblast co-culture dampened the ability of high concentrations of FG-4592 to increase bone resorption.This data provides support for the therapeutic use of PHD enzyme inhibitors to improve bone formation and/or reduce bone loss for treatment of osteolytic pathologies, and indicates that FG-4592 might also act to inhibit the formation and activity of the osteoclasts that drive osteolysis.

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2-NPPA Mitigates Osteoclastogenesis via Reducing TRAF6-Mediated c-fos Expression

Frontiers in Pharmacology ◽

10.3389/fphar.2020.599081 ◽

2021 ◽

Vol 11 ◽

Author(s):

Zhihao Chen ◽

Mina Ding ◽

Eunjin Cho ◽

Jihyoun Seong ◽

Sunwoo Lee ◽

...

Keyword(s):

Bone Resorption ◽

Bone Loss ◽

Bone Destruction ◽

Inhibitory Effect ◽

Bone Diseases ◽

Point Of View ◽

A Cell ◽

Fos Expression

Excessive bone resorption leads to bone destruction in pathological bone diseases. Osteoporosis, which occurs when osteoclast-mediated bone resorption exceeds osteoblast-mediated bone synthesis, is regarded a global health challenge. Therefore, it is of great importance to identify agents that can regulate the activity of osteoclasts and prevent bone diseases mediated mainly by bone loss. We screened compounds for this purpose and found that 2-(2-chlorophenoxy)-N-[2-(4-propionyl-1piperazinyl) phenyl] acetamide (2-NPPA) exhibited a strong inhibitory effect on osteoclastogenesis. 2-NPPA suppressed the mRNA and protein expression of several osteoclast-specific markers and blocked the formation of mature osteoclasts, reducing the F-actin ring formation and bone resorption activity. In a cell signaling point of view, 2-NPPA exhibited a significant inhibitory effect on the phosphorylation of nuclear factor kappa-B (NF-κB) and c-fos expression in vitro and prevented ovariectomy-induced bone loss in vivo. These findings highlighted the potential of 2-NPPA as a drug for the treatment of bone loss-mediated disorders.

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Thonzonium bromide inhibits RANKL-induced osteoclast formation and bone resorption in vitro and prevents LPS-induced bone loss in vivo

Biochemical Pharmacology ◽

10.1016/j.bcp.2016.02.013 ◽

2016 ◽

Vol 104 ◽

pp. 118-130 ◽

Cited By ~ 18

Author(s):

Xiang Zhu ◽

Jun J. Gao ◽

Euphemie Landao-Bassonga ◽

Nathan J. Pavlos ◽

An Qin ◽

...

Keyword(s):

Bone Resorption ◽

Bone Loss ◽

Osteoclast Formation

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A novel BRD4 inhibitor suppresses osteoclastogenesis and ovariectomized osteoporosis by blocking RANKL-mediated MAPK and NF-κB pathways

Cell Death and Disease ◽

10.1038/s41419-021-03939-7 ◽

2021 ◽

Vol 12 (7) ◽

Author(s):

Ying Liu ◽

Wenjie Liu ◽

Ziqiang Yu ◽

Yan Zhang ◽

Yinghua Li ◽

...

Keyword(s):

Bone Loss ◽

Osteoporosis Treatment ◽

Inhibitory Effect ◽

Specific Gene ◽

Actin Ring ◽

Treatment Target ◽

Significant Inhibitory Effect ◽

Promising Treatment

AbstractBromodomain-containing protein 4 (BRD4) has emerged as a promising treatment target for bone-related disorders. (+)-JQ1, a thienotriazolodiazepine compound, has been shown to inhibit pro-osteoclastic activity in a BRD4-dependent approach and impede bone loss caused by ovariectomy (OVX) in vivo. However, clinical trials of (+)-JQ1 are limited because of its poor druggability. In this study, we synthesized a new (+)-JQ1 derivative differing in structure and chirality. One such derivative, (+)-ND, exhibited higher solubility and excellent inhibitory activity against BRD4 compared with its analogue (+)-JQ1. Interestingly, (-)-JQ1 and (-)-ND exhibited low anti-proliferative activity and had no significant inhibitory effect on RANKL-induced osteoclastogenesis as compared with (+)-JQ1 and (+)-ND, suggesting the importance of chirality in the biological activity of compounds. Among these compounds, (+)-ND displayed the most prominent inhibitory effect on RANKL-induced osteoclastogenesis. Moreover, (+)-ND could inhibit osteoclast-specific gene expression, F‐actin ring generation, and bone resorption in vitro and prevent bone loss in OVX mice. Collectively, these findings indicated that (+)-ND represses RANKL‐stimulated osteoclastogenesis and averts OVX-triggered osteoporosis by suppressing MAPK and NF-κB signalling cascades, suggesting that it may be a prospective candidate for osteoporosis treatment.

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