scholarly journals Undercarboxylated osteocalcin inhibits the early differentiation of osteoclast mediated by Gprc6a

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e10898
Author(s):  
Hailong Wang ◽  
Jinqiao Li ◽  
Zihan Xu ◽  
Feng Wu ◽  
Hongyu Zhang ◽  
...  

Osteocalcin (OCN) was the most abundant noncollagen protein and considered as an endocrine factor. However, the functions of Undercarboxylated osteocalcin (ucOCN) on osteoclast and bone resorption are not well understood. In the present study, preosteoclast RAW264.7 cells and bone marrow mononuclear cells (BMMs) were treated with ucOCN purified from prokaryotic bacteria. Our results showed that ucOCN attenuated the proliferation of RAW264.7 cells with a concentration dependant manner by MTS assay. Scrape wounding assay revealed the decreased motility of RAW264.7 cells after ucOCN treatment. RT-qPCR results manifested the inhibitory effects of ucOCN on the expression of osteoclastic marker genes in RAW264.7 cells during inducing differentiation of RANKL. It was also observed that ucOCN inhibited the formation of multinucleated cells from RAW264.7 cells and BMMs detected by TRAP staining. The number and area of bone resorb pits were also decreased after treatment with ucOCN during their osteoclast induction by toluidine blue staining. The formation and integrity of the osteoclast actin ring were impaired by ucOCN by immunofluorescent staining. Time dependant treatment of ucOCN during osteoclastic induction demonstrated the inhibitory effects mainly occurred at the early stage of osteoclastogenesis. Signaling analysis of luciferase activity of the CRE or SRE reporter and ERK1/2 phosphorylation showed the selective inhibitor or siRNA of Gprc6a (a presumptive ucOCN receptor) could attenuate the promotion of ucOCN on CRE-luciferase activity. Taken together, we provided the first evidence that ucOCN had negative effects on the early differentiation and bone resorption of osteoclasts via Gprc6a.

Endocrinology ◽  
2010 ◽  
Vol 151 (10) ◽  
pp. 4613-4625 ◽  
Author(s):  
Masakazu Kogawa ◽  
David M. Findlay ◽  
Paul H. Anderson ◽  
Renee Ormsby ◽  
Cristina Vincent ◽  
...  

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.


2019 ◽  
Vol 20 (20) ◽  
pp. 5196 ◽  
Author(s):  
Zhihao Chen ◽  
Eunjin Cho ◽  
Jinkyung Lee ◽  
Sunwoo Lee ◽  
Tae-Hoon Lee

Osteoclasts are poly-nuclear cells that resorb mineral components from old or damaged bone tissue. Primary mononuclear cells are activated by receptor activator of nuclear factor kappa-Β ligand (RANKL) and differentiate into large multinucleated cells. Dysregulation of osteoclast differentiation can lead to pathological bone loss and destruction. Many studies have focused on the development of new molecules to regulate RANKL-mediated signaling. In this study, N-[2-(4-acetyl-1-piperazinyl)phenyl]-2-(2-chlorophenoxy) acetamide (PPOA-N-Ac-2-Cl) led to a significant decrease in the formation of multinucleated tartrate-resistant acid phosphatase (TRAP)-positive cells in a dose-dependent manner, without inducing significant cytotoxicity. PPOA-N-Ac-2-Cl affected the expression of osteoclast-specific marker genes, such as TRAF6, c-fos, DC-STAMP, NFATc1, MMP9, CtsK, and TRAP (Acp5), during RANKL-mediated osteoclastogenesis. Moreover, PPOA-N-Ac-2-Cl significantly attenuated the protein levels of CtsK, a critical protease involved in bone resorption. Accordingly, bone resorption activity and F-actin ring formation decreased in the presence of PPOA-N-Ac-2-Cl. In conclusion, this study shows that PPOA-N-Ac-2-Cl acts as an inhibitor of osteoclast differentiation and may serve as a potential candidate agent for the treatment of osteoclast-related bone diseases by virtue of attenuating bone resorption.


1984 ◽  
Vol 92 (3) ◽  
pp. 322-328 ◽  
Author(s):  
Hiroshi Moriyama ◽  
Cheng Huang Chun ◽  
Maxwell Abramson ◽  
Michimasa Kato

Collagenase was identified within naturally occurring rat chronic otitis media by the use of an immunohistochemical technique with peroxidase-antiperoxidase to stain the paraffin. Collagenase was found in fibroblasts, mononuclear cells, and osteoclast cells in the bone-resorbing area. Collagenase was found only in fibroblasts in contact with epithelial basal cells. Macrophages from rat peritoneum were cultured with different concentrations of a lipopolysaccharide. The prostaglandin E2 level reached a maximum during the 12-to 24-hour period in the presence of endotoxin. This prostaglandin E2 was confirmed by immunofluorescent staining. The endotoxin-activated macrophage produced an insignificant amount of collagenase. These findings suggest that activated macrophages may be able to stimulate fibroblast collagenase production through the chemical mediator prostaglandin E2. Also, the interaction between fibroblasts and epidermal cells appears to encourage and enhance the biochemical events resulting in bone resorption in chronic otitis media.


2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Wenhan Zhao ◽  
Zhusong Huang ◽  
Yu Lin ◽  
Jinfu Lan ◽  
Xi Gao

Objective. This study is aimed at studying the effect of zoledronate (ZOL) on the differentiation of osteoclast precursor RAW264.7 cells induced by titanium (Ti) particles and explores the possibility of preventing and treating periprosthetic osteoporosis using ZOL. Methods. RAW264.7 cells were cultured in vitro. Ti particles were prepared. The cell proliferation curve of RAW264.7 cells was plotted using the MTT assay to find the best concentration of ZOL for intervention. The cells were divided into three groups: control, Ti particles, and Ti particles+ZOL. The cell morphology was observed using tartaric acid–resistant acid phosphatase (TRAP) staining, and the activity of TRAP in cell supernatant was determined using the biochemical method. The number of bone resorption lacunae was detected using toluidine blue staining. The mRNA expression of RANK, NFATcl, CAII, and MMP-9 was detected using real-time polymerase chain reaction. The protein expression of RANK, NFATcl, and MMP-9 was detected using Western blot analysis. Results. Ti particles stimulated the differentiation of RAW264.7 cells into osteoclasts. They also increased the activity of TRAP, number of bone resorption lacunae, and mRNA and protein expression of RANK, NFATcl, and MMP-9. However, ZOL could suppress the effect of TI particles on the osteoclast differentiation of RAW264.7 cells. Conclusions. ZOL could effectively inhibit the differentiation of RAW264.7 cells into osteoclasts induced by Ti particles, decrease the activity of TRAP, reduce the number of bone resorption lacunae, and decrease the mRNA and protein expression of RANK, NFATcl, and MMP-9. Hence, it may be a promising candidate for preventing and treating periprosthetic osteoporosis after the artificial joint operation.


1982 ◽  
Vol 243 (6) ◽  
pp. E499-E504
Author(s):  
N. S. Krieger ◽  
P. H. Stern

The cardiotonic agent amrinone has been postulated to directly affect Na-Ca exchange. Because stimulated bone resorption has been proposed to require Na-Ca exchange, we examined the effects of amrinone on bone. Amrinone inhibited release of Ca from neonatal mouse calvaria in organ culture stimulated by parathyroid hormone (PTH), 1,25-dihydroxyvitamin d3, or prostaglandin E2. Inhibition was dose dependent and maximal at 2 X 10(-4) M. The effect of amrinone differed from the inhibitory effects of calcitonin, ouabain, or nigericin in that 1) 6-h exposure to amrinone alone prevented the effect of subsequently added PTH; 2) amrinone was only partially effective if added after resorption was initiated by 24-h treatment with PTH; 3) coincubation with amrinone and PTH during the first 48 h of culture allowed for a response to PTH after amrinone was removed; no such protection by a stimulator occurred with ouabain or nigericin. Also submaximal concentrations of amrinone plus calcitonin, ouabain, or nigericin gave greater than additive inhibition of Ca release. Amrinone had no effect on basal bone cAMP or on the acute stimulation of cAMP by PTH. The results suggest that amrinone could have a more direct interaction with the pathway involved in stimulated bone resorption than the other inhibitors.


2021 ◽  
Vol 16 (2) ◽  
pp. 1934578X2199914
Author(s):  
Ninh Khac Ban ◽  
Bui Huu Tai ◽  
Vu Kim Thu ◽  
Phan Van Kiem

A new δ-truxinic acid sucrose diester and a new ε-truxillic acid sucrose diester (named trigohonbanosides E and F) were isolated from the leaves of Trigonostemon honbaensis. Their chemical structures were determined by extensive analysis of their HR-ESI-MS and NMR spectra. At a concentration of 20 µM, trigohonbanosides E and F exhibited weak inhibitory effects on NO production in LPS-activated RAW264.7 cells with inhibitory percentages of 22.7% ± 1.1% and 18.5% ± 1.4%, respectively.


Author(s):  
Arnaud Boudenot ◽  
stephane PALLU ◽  
Rustem UZBEKOV ◽  
Eric DOLLEANS ◽  
Hechmi Toumi ◽  
...  

The effects of treadmill interval training (IT) and free fall exercise were evaluated on bone parameters including osteocyte related characteristics. Thirty-eight 4-month-old male Wistar rats were randomly divided into a control group (C) and exercise groups: IT, 10 free fall impacts/day with a 10s (FF10) or 20s interval between drops (FF20), 5 days/week, for 9 weeks. We assessed: BMD, microarchitecture by µCT, mechanical strength by a three-point bending test, density and occupancy of the osteocyte lacunae by toluidine blue staining, osteocalcin and NTx systemic levels by ELISA, and bone tissue Sost mRNA expression by RT-PCR. NTx levels were significantly lower in exercise groups as compared to C. In exercise groups Sost mRNA expression was significantly lower than in C. Tb.N was significantly higher for IT and FF20 compared to C; Tb.Sp was significantly lower in FF10 compared to C. Both IT and FF20 were associated with higher tibial lacunar density as compared to FF10. Compared to FF10, IT fat mass was lower, while tibial osteocyte lacunae occupancy and systemic osteocalcin level were higher. All exercise modes were efficient in reducing bone resorption. Both IT and FF impact with appropriate recovery periods might be beneficial for bone health and osteocyte related characteristics. Novelty bullets: • Interval training is beneficial for bone mineral density • Exercises decreased both bone resorption and inhibition of bone formation (sost mRNA) • Longer interval recovery time favors osteocyte lacunae density


2012 ◽  
Vol 30 (1) ◽  
pp. 123-136 ◽  
Author(s):  
Chun Guo ◽  
Guo-qing Hou ◽  
Xue-dong Li ◽  
Xue Xia ◽  
Dong-xin Liu ◽  
...  

Endocrine ◽  
2021 ◽  
Author(s):  
Miriam E. A. Tschaffon ◽  
Stefan O. Reber ◽  
Astrid Schoppa ◽  
Sayantan Nandi ◽  
Ion C. Cirstea ◽  
...  

Abstract Purpose Endochondral ossification, which involves transdifferentiation of chondrocytes into osteoblasts, is an important process involved in the development and postnatal growth of most vertebrate bones as well as in bone fracture healing. To study the basic molecular mechanisms of this process, a robust and easy-to-use in vitro model is desirable. Therefore, we aimed to develop a standardized in vitro assay for the transdifferentiation of chondrogenic cells towards the osteogenic lineage. Methods Murine chondrogenic ATDC5 cells were differentiated into the chondrogenic lineage for seven days and subsequently differentiated towards the osteogenic direction. Gene expression analysis of pluripotency, as well as chondrogenic and osteogenic markers, cell–matrix staining, and immunofluorescent staining, were performed to assess the differentiation. In addition, the effects of Wnt3a and lipopolysaccharides (LPS) on the transdifferentiation were tested by their addition to the osteogenic differentiation medium. Results Following osteogenic differentiation, chondrogenically pe-differentiated cells displayed the expression of pluripotency and osteogenic marker genes as well as alkaline phosphatase activity and a mineralized matrix. Co-expression of Col2a1 and Col1a1 after one day of osteogenic differentiation indicated that osteogenic cells had differentiated from chondrogenic cells. Wnt3a increased and LPS decreased transdifferentiation towards the osteogenic lineage. Conclusion We successfully established a rapid, standardized in vitro assay for the transdifferentiation of chondrogenic cells into osteogenic cells, which is suitable for testing the effects of different compounds on this cellular process.


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