scholarly journals Aesculetin Inhibits Osteoclastic Bone Resorption through Blocking Ruffled Border Formation and Lysosomal Trafficking

2020 ◽  
Vol 21 (22) ◽  
pp. 8581
Author(s):  
Woojin Na ◽  
Eun-Jung Lee ◽  
Min-Kyung Kang ◽  
Yun-Ho Kim ◽  
Dong Yeon Kim ◽  
...  
Keyword(s):  
Bone Resorption ◽  
Bone Matrix ◽  
Osteoclast Differentiation ◽  
Nuclear Factor Κb ◽  
Small Gtpase ◽  
Raw 264.7 Cells ◽  
Pleckstrin Homology Domain ◽  
Αvβ3 Integrin ◽  
Lysosomal Trafficking ◽  
Ruffled Border

For the optimal resorption of mineralized bone matrix, osteoclasts require the generation of the ruffled border and acidic resorption lacuna through lysosomal trafficking and exocytosis. Coumarin-type aesculetin is a naturally occurring compound with anti-inflammatory and antibacterial effects. However, the direct effects of aesculetin on osteoclastogenesis remain to be elucidated. This study found that aesculetin inhibited osteoclast activation and bone resorption through blocking formation and exocytosis of lysosomes. Raw 264.7 cells were differentiated in the presence of 50 ng/mL receptor activator of nuclear factor-κB ligand (RANKL) and treated with 1–10 μM aesculetin. Differentiation, bone resorption, and lysosome biogenesis of osteoclasts were determined by tartrate-resistance acid phosphatase (TRAP) staining, bone resorption assay, Western blotting, immunocytochemical analysis, and LysoTracker staining. Aesculetin inhibited RANKL-induced formation of multinucleated osteoclasts with a reduction of TRAP activity. Micromolar aesculetin deterred the actin ring formation through inhibition of induction of αvβ3 integrin and Cdc42 but not cluster of differentiation 44 (CD44) in RANKL-exposed osteoclasts. Administering aesculetin to RANKL-exposed osteoclasts attenuated the induction of autophagy-related proteins, microtubule-associated protein light chain 3, and small GTPase Rab7, hampering the lysosomal trafficking onto ruffled border crucial for bone resorption. In addition, aesculetin curtailed cellular induction of Pleckstrin homology domain-containing protein family member 1 and lissencephaly-1 involved in lysosome positioning to microtubules involved in the lysosomal transport within mature osteoclasts. These results demonstrate that aesculetin retarded osteoclast differentiation and impaired lysosomal trafficking and exocytosis for the formation of the putative ruffled border. Therefore, aesculetin may be a potential osteoprotective agent targeting RANKL-induced osteoclastic born resorption for medicinal use.

scholarly journals Aesculetin Inhibits Bone Resorption Through Down-Regulating Differentiation and Lysosomal Formation in Osteoclasts

2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 442-442
Author(s):  
WooJin Na ◽  
Young-Hee Kang
Keyword(s):  
Bone Resorption ◽  
Osteoclast Differentiation ◽  
Cathepsin K ◽  
Small Gtpase ◽  
Raw 264.7 Cells ◽  
Treatment Of Osteoporosis ◽  
Funding Sources ◽  
Lysosome Biogenesis ◽  
Cellular Expression ◽  
Secretory Lysosome

Abstract Objectives For the optimal resorption of mineralized bone extracellular matrix, osteoclasts require the generation of a resorption lacuna characterized by the presence of specific proteases and a low pH. Thus, bone resorption by osteoclasts highly rely on lysosomes, the organelles specialized in intra- and extracellular material degradation. Aesculetin, a derivative of coumarin, possesses anti-inflammatory and anti-bacterial effects. The purpose of this study was to identify that aesculetin inhibited osteoclast differentiation and bone resorption through down-regulating lysosomal formation. Methods Raw 264.7 cells were cultured for 5 days on α-MEM with 10% FBS in the absence or presence of 50 ng/ml RANKL and 1–10 μM aesculetin. Tartrate-resistance acid phosphatase (TRAP) staining and bone resorption assay were performed by using assay kits. Western blotting was conducted with antibodies of target proteins involved in activation and lysosome biogenesis of osteoclasts. Immunocytochemical analysis employed LysoTracker for lysosome staining and α-tubulin antibody conjugated with FITC. Results Aesculetin inhibited RANKL-treated formation of multinucleated osteoclasts with a reduction of TRAP activity. When 1–10 μM aesculetin was treated to RANKL-exposed osteoclasts, the bone resorption was highly suppressed in osteoclasts. In addition, aesculetin reduced cellular expression of carbonic anhydrase II, vacuolar-type H (+)-ATPase D2 and cathepsin K elevated by RANKL, all involved in the bone resorption. Furthermore, aesculetin curtailed cellular induction of autophagy-related (Atg)5, Atg7 and small GTPase Rab7 elevated by RANKL for lysosome transportation/secretion and bone resorption in osteoclasts. Conclusions Aesculetin was effective in retarding osteoclast differentiation and secretory lysosome formation for osteoclast resorption, indicating that this compound may be a potential agent for the treatment of osteoporosis. Funding Sources No funding sources to report.

The cell biology of osteoclast function

2000 ◽  
Vol 113 (3) ◽  
pp. 377-381 ◽  
Author(s):  
H.K. Vaananen ◽  
H. Zhao ◽  
M. Mulari ◽  
J.M. Halleen
Keyword(s):  
Bone Resorption ◽  
Cell Biology ◽  
Degradation Products ◽  
Bone Matrix ◽  
Organic Matrix ◽  
Endosomal Membrane ◽  
Multinucleated Cells ◽  
Sealing Zone ◽  
Ruffled Border ◽  
Osteoclast Function

Osteoclasts are multinucleated cells responsible for bone resorption. They have developed an efficient machinery for dissolving crystalline hydroxyapatite and degrading organic bone matrix rich in collagen fibers. When initiating bone resorption, osteoclasts become polarized, and three distinct membrane domains appear: a ruffled border, a sealing zone and a functional secretory domain. Simultaneously, the cytoskeleton undergoes extensive re-organisation. During this process, the actin cytoskeleton forms an attachment ring at the sealing zone, the membrane domain that anchors the resorbing cell to bone matrix. The ruffled border appears inside the sealing zone, and has several characteristics of late endosomal membrane. Extensive vesicle transport to the ruffled border delivers hydrochloric acid and proteases to an area between the ruffled border and the bone surface called the resorption lacuna. In this extracellular compartment, crystalline hydroxyapatite is dissolved by acid, and a mixture of proteases degrades the organic matrix. The degradation products of collagen and other matrix components are endocytosed, transported through the cell and exocytosed through a functional secretory domain. This transcytotic route allows osteoclasts to remove large amounts of matrix-degradation products without losing their tight attachment to underlying bone. It also facilitates further processing of the degradation products intracellularly during the passage through the cell.

Edgeworthia papyrifera Regulates Osteoblast and Osteoclast Differentiation In Vitro and Exhibits Anti-osteoporosis Activity in Animal Models of Osteoporosis

Planta Medica ◽  
2019 ◽  
Vol 85 (09/10) ◽  
pp. 766-773 ◽  
Author(s):  
Pansoo Kim ◽  
Yeon-Ju Nam ◽  
Woo Jung Kim ◽  
Jin Kyu Kim ◽  
Gyeongbeen Lee ◽  
...  
Keyword(s):  
Bone Resorption ◽  
Animal Models ◽  
Osteoclast Differentiation ◽  
Raw 264.7 Cells ◽  
Tartrate Resistant Acid Phosphatase ◽  
Raw 264.7 ◽  
Treatment Of Osteoporosis ◽  
Increased Risk ◽  
Interesting Candidate

AbstractOsteoporosis is a clinical condition characterized by low bone strength that leads to an increased risk of fracture. Strategies for the treatment of osteoporosis involve inhibition of bone resorption by osteoclasts and an increase of bone formation by osteoblasts. Here, we identified the extract derived from the stem part of Edgeworthia papyrifera that enhanced differentiation of MC3T3-E1 cells to osteoblast-like cells and inhibited osteoclast differentiation of RAW 264.7 cells in vitro. In support of our observation, rutin and daphnoretin, which were previously reported to inhibit osteoclast differentiation, were identified in E. papyrifera extract. In an animal model of osteoporosis, the ovariectomy-induced increases in bone resorption biomarkers such as pyridinoline and tartrate-resistant acid phosphatase were significantly reduced by E. papyrifera extract administration at 25.6 and 48.1%, respectively. Furthermore, the ovariectomy-induced bone loss in animal models of osteoporosis was significantly prevented by the administration of E. papyrifera in our study. Taking these observations into account, we suggest that E. papyrifera is an interesting candidate for further exploration as an anti-osteoporotic agent.

scholarly journals Zinc modifies the effect of phyto-oestrogens on osteoblast and osteoclast differentiationin vitro

2012 ◽  
Vol 108 (10) ◽  
pp. 1736-1745 ◽  
Author(s):  
Sahar Karieb ◽  
Simon W. Fox
Keyword(s):  
Bone Resorption ◽  
Mrna Expression ◽  
Bone Matrix ◽  
Osteoclast Differentiation ◽  
Dietary Factors ◽  
Type I ◽  
Osteoclast Activity ◽  
Post Menopausal Osteoporosis ◽  
Osteoblast Activity ◽  
Anabolic Action

Osteoblast and osteoclast activity is disrupted in post-menopausal osteoporosis. Thus, to fully address this imbalance, therapies should reduce bone resorption and promote bone formation. Dietary factors such as phyto-oestrogens and Zn have beneficial effects on osteoblast and osteoclast activity. However, the effect of combinations of these factors has not been widely studied. We therefore examined the effect of coumestrol, daidzein and genistein in the presence or absence of zinc sulphate (Zn) on osteoclast and osteoblast activity. Osteoclast differentiation and bone resorption were significantly reduced by coumestrol (10− 7 m), daidzein (10− 5 m) and genistein (10− 7 m); and this direct anti-osteoclastic action was unaffected by Zn (10− 5 m). In addition, Zn augmented the inhibitory effect of phyto-oestrogens on the osteoblast-derived stimulus for osteoclast formation, significantly reducing the ratio of receptor activator of NF-κB ligand (RANKL)-to-osteoprotegerin mRNA expression in human osteoblast. We then examined the effect of these compounds on osteoblast activity. Mineralisation was enhanced by coumestrol (10− 5to 10− 7 m), daidzein (10− 5to 10− 6 m) and genistein (10− 5 m); and Zn significantly augmented this response. Zn and phyto-oestrogens also significantly enhanced alkaline phosphatase activity and Runt-related transcription factor 2 (Runx2) mRNA expression. On the other hand, Zn blunted phyto-oestrogen-induced type I collagen and osteocalcin expression and suppressed coumestrol and daidzein-stimulated osterix expression. Zn may therefore modify the anabolic action of phyto-oestrogens, promoting characteristics associated with early rather than late stages of osteoblast differentiation. Our data suggest that while Zn enhances the anti-osteoclastic effect of phyto-oestrogens, it may limit aspects of their anabolic action on bone matrix formation.

scholarly journals The emerging role of IMD 0354 on bone homeostasis by suppressing osteoclastogenesis and bone resorption, but without affecting bone formation

2019 ◽  
Vol 10 (9) ◽  
Author(s):  
Wenxiang Chen ◽  
Ziang Xie ◽  
Pan Tang ◽  
Yongli Wang ◽  
Zhiwei Jie ◽  
...  
Keyword(s):  
Bone Resorption ◽  
Bone Formation ◽  
Osteoclast Differentiation ◽  
Nuclear Factor Κb ◽  
Mapk Signaling ◽  
Mitogen Activated Protein Kinase ◽  
Therapeutic Drug ◽  
Tartrate Resistant Acid Phosphatase ◽  
Nuclear Factor ◽  
Bone Homeostasis

Abstract Osteoporosis is caused by an imbalance between bone formation and bone resorption. Receptor activator of nuclear factor-κB ligand (RANKL) promotes the activity and differentiation of osteoclasts via activating the nuclear factor-κB (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways. IMD 0354 is a selective molecular inhibitor of inhibitor of NF-κB kinase subunit beta (IKKβ) and effective for treatment of acute and subacute inflammatory diseases through the suppression of NF-κB activation. However, the effect of IMD 0354 on bone homeostasis is unknown. In this study, we demonstrated that IMD 0354 significantly attenuated ovariectomy-induced bone loss and inhibited osteoclastogenesis in mice, whereas bone formation was not affected. Additionally, IMD 0354 dramatically inhibited osteoclast differentiation and function induced by RANKL and macrophage colony-stimulating factor in bone marrow monocytes as verified by tartrate-resistant acid phosphatase (TRAP) staining as well as bone resorption assay in vitro. Subsequently, we found that activation of NF-κB signaling and the ERK/c-Fos axis were blunted during osteoclast formation induced by RANKL. Transcription factors nuclear factor of activated T cells c1 (NFATc1) and c-Fos were suppressed with the decreased expression of osteoclast-related genes by IMD 0354. Our findings suggest that IMD 0354 could be a potential preventive and therapeutic drug for osteoporosis.

scholarly journals Cxcl9l and Cxcr3.2 regulate recruitment of osteoclast progenitors to bone matrix in a medaka osteoporosis model

2020 ◽  
Vol 117 (32) ◽  
pp. 19276-19286 ◽  
Author(s):  
Quang Tien Phan ◽  
Wen Hui Tan ◽  
Ranran Liu ◽  
Sudha Sundaram ◽  
Anita Buettner ◽  
...  
Keyword(s):  
Bone Resorption ◽  
Structural Integrity ◽  
Bone Matrix ◽  
Osteoclast Differentiation ◽  
Ectopic Expression ◽  
Live Imaging ◽  
Bone Homeostasis ◽  
Cell Recruitment ◽  
Receptor Activator ◽  
Chemokine Ligand

Bone homeostasis requires continuous remodeling of bone matrix to maintain structural integrity. This involves extensive communication between bone-forming osteoblasts and bone-resorbing osteoclasts to orchestrate balanced progenitor cell recruitment and activation. Only a few mediators controlling progenitor activation are known to date and have been targeted for intervention of bone disorders such as osteoporosis. To identify druggable pathways, we generated a medaka (Oryzias latipes) osteoporosis model, where inducible expression of receptor-activator of nuclear factor kappa-Β ligand (Rankl) leads to ectopic formation of osteoclasts and excessive bone resorption, which can be assessed by live imaging. Here we show that upon Rankl induction, osteoblast progenitors up-regulate expression of the chemokine ligand Cxcl9l. Ectopic expression of Cxcl9l recruitsmpeg1-positive macrophages to bone matrix and triggers their differentiation into osteoclasts. We also demonstrate that the chemokine receptor Cxcr3.2 is expressed in a distinct subset of macrophages in the aorta-gonad-mesonephros (AGM). Live imaging revealed that upon Rankl induction, Cxcr3.2-positive macrophages get activated, migrate to bone matrix, and differentiate into osteoclasts. Importantly, mutations incxcr3.2prevent macrophage recruitment and osteoclast differentiation. Furthermore, Cxcr3.2 inhibition by the chemical antagonists AMG487 and NBI-74330 also reduced osteoclast recruitment and protected bone integrity against osteoporotic insult. Our data identify a mechanism for progenitor recruitment to bone resorption sites and Cxcl9l and Cxcr3.2 as potential druggable regulators of bone homeostasis and osteoporosis.

scholarly journals Cirsium Setidens Extracts Abrogate Actin Ring Formation and Bone-Resorbing Osteoclasts Through Inhibition of Core-Linked CD44 and Diffuse Cloud-Associated αvβ3 Integrin

2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 416-416
Author(s):  
Soo-il Kim ◽  
Young-Hee Kang
Keyword(s):  
Bone Resorption ◽  
Bone Matrix ◽  
Ring Formation ◽  
Activity Measurement ◽  
Αvβ3 Integrin ◽  
Actin Ring ◽  
Funding Sources ◽  
Core Proteins ◽  
Diffuse Cloud ◽  
Cirsium Setidens

Abstract Objectives Since enhanced bone resorption cause skeletal diseases, there is a growing need in therapeutics for combating bone-resorbing osteoclasts. Botanical antioxidants are being increasingly investigated for their health-promoting effects on bone. Cirsium setidens (Korean thistle) contains linarin, luteolin, pectolinarin, hispidulin, and apigenin with antioxidant and hepatoprotective effects. This study examined whether 1–20 μg/ml Cirsium setidens extracts (CSE) inhibited osteoclastogenesis of RANKL-exposed RAW 264.7murine. Methods RAW 264.7 murine macrophages were incubated with 1–20 μg/ml CSE for 5 days in the presence of 50 ng/ml RANKL. Tartrate-resistance acid phosphatase (TRAP) staining and its activity measurement were performed. Western blotting was done with target proteins involved in the osteoclast activation. Results Nontoxic CSE attenuated the RANKL-induced macrophage differentiation into multinucleated osteoclasts, and curtailed bone resorption through reducing lacunar acidification and bone matrix degradation. Linarin and pectolinarin were identified as major components of CSE, where linarin but not pectolinarin were effective in inhibiting formation of TRAP-positive osteoclasts. Linarin-rich CSE diminished the induction of αvβ3 integrin-associated proteins of paxillin, Pyk2 and gelsolin. Additionally, CSE deterred actin ring formation with attenuation of induction of F-actin-enriched podosome core proteins of CD44, Arp2/3 and cortactin. Nontoxic linarin and its aglycone acacetin reduced focal contact of osteoclasts to RGD peptide. The inhibition of integrin-mediated actin ring formation by CSE entailed disruption of TRAF6-c-Src-PI3K signaling of osteoclasts. Conclusions CSE was effective in retarding focal adhesion to bone matrix and active bone resorption of osteoclast via inhibition of core-linked CD44 and diffuse cloud-associated αvβ3 integrin. Funding Sources This work was supported by the National Research Foundation of Korea(NRF) grant funded by the Korea government(MSIT) (2019R1A2C1003218).

scholarly journals Cell-mediated extracellular acidification and bone resorption: evidence for a low pH in resorbing lacunae and localization of a 100-kD lysosomal membrane protein at the osteoclast ruffled border.

1985 ◽  
Vol 101 (6) ◽  
pp. 2210-2222 ◽  
Author(s):  
R Baron ◽  
L Neff ◽  
D Louvard ◽  
P J Courtoy
Keyword(s):  
Bone Resorption ◽  
Membrane Protein ◽  
Ammonium Chloride ◽  
Bone Matrix ◽  
Low Ph ◽  
Lysosomal Membrane ◽  
Cell Biol ◽  
Extracellular Compartment ◽  
Ruffled Border ◽  
Lysosomal Membrane Protein

The extracellular compartment where bone resorption occurs, between the osteoclast and bone matrix, is shown in this report to be actively acidified. The weak base acridine orange accumulates within this compartment but dissipates after incubation with ammonium chloride. Upon removal of ammonium chloride, the cells are able to rapidly reacidify this compartment. The highly convoluted plasma membrane of the osteoclast facing this acidic compartment (ruffled border) is shown to contain a 100-kD integral membrane protein otherwise present in limiting membranes of lysosomes and other related acidified organelles (Reggio, H., D. Bainton, E. Harms, E. Coudrier, and D. Louvard, 1984, J. Cell Biol., 99:1511-1526; Tougard, C., D. Louvard, R. Picart, and A. Tixier-Vidal, 1985, J. Cell Biol. 100:786-793). Antibodies recognizing this 100-kD lysosomal membrane protein cross-react with a proton-pump ATPase from pig gastric mucosae (Reggio, H., D. Bainton, E. Harms, E. Coudrier, and D. Louvard, 1984, J. Cell Biol., 99:1511-1526), therefore raising the possibility that it plays a role in the acidification of both intracellular organelles and extracellular compartments. Lysosomal enzymes are also directionally secreted by the osteoclast into the acidified extracellular compartment which can therefore be considered as the functional equivalent of a secondary lysosome with a low pH, acid hydrolases, the substrate, and a limiting membrane containing the 100-kD antigen.

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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