CGRP inhibits osteoprotegerin production in human osteoblast-like cells via cAMP/PKA-dependent pathway

2006 ◽  
Vol 291 (3) ◽  
pp. C529-C537 ◽  
Author(s):  
I. Villa ◽  
E. Mrak ◽  
A. Rubinacci ◽  
F. Ravasi ◽  
F. Guidobono
Keyword(s):  
Mononuclear Cells ◽  
Human Peripheral Blood ◽  
Primary Cultures ◽  
Nuclear Factor Κb ◽  
Conditioned Media ◽  
Fine Tuning ◽  
Tartrate Resistant Acid Phosphatase ◽  
Nuclear Factor ◽  
Human Osteoblast ◽  
Receptor Activator

The osteoprotegerin (OPG)/receptor activator of nuclear factor-κB ligand (RANKL)/receptor activator of nuclear factor-κB (RANK) system was evaluated as a potential target of CGRP anabolic activity on bone. Primary cultures of human osteoblast-like cells (hOB) express calcitonin receptor-like receptor (CLR) and receptor activity modifying protein 1, and, because CGRP stimulates cAMP (one of the modulators of OPG production in osteoblasts), it was investigated whether it affects OPG secretion and expression in hOB. CGRP treatment of hOB (10−11 M–10−7 M) dose-dependently inhibited OPG secretion with an EC50 of 1.08 × 10−10 M, and also decreased its expression. This action was blocked by the antagonist CGRP8–37. Forskolin, a stimulator of cAMP production, and dibutyryl cAMP also reduced the production of OPG. CGRP (10−8 M) enhanced protein kinase A (PKA) activity in hOB, and hOB exposure to the PKA inhibitor, H89 (2 × 10−6 M), abolished the inhibitory effect of CGRP on OPG secretion. Conditioned media from CGRP-treated hOB increased the number of multinucleated tartrate-resistant acid phosphatase-positive cells and the secretion of cathepsin K in human peripheral blood mononuclear cells compared with the conditioned media of untreated hOB. These results show that the cAMP/PKA pathway is involved in the CGRP inhibition of OPG mRNA and protein secretion in hOB and that this effect favors osteoclastogenesis. CGRP could thus modulate the balance between osteoblast and osteoclast activity, participating in the fine tuning of all of the bone remodeling phases necessary for the subsequent anabolic effect.

scholarly journals The Role of miR-21 in Osteoblasts–Osteoclasts Coupling In Vitro

Cells ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 479 ◽  
Author(s):  
Agnieszka Smieszek ◽  
Klaudia Marcinkowska ◽  
Ariadna Pielok ◽  
Mateusz Sikora ◽  
Lukas Valihrach ◽  
...  
Keyword(s):  
Cathepsin K ◽  
Nuclear Factor Κb ◽  
Tartrate Resistant Acid Phosphatase ◽  
Type I ◽  
Nuclear Factor ◽  
Paracrine Signaling ◽  
Receptor Activator ◽  
The Impact

MiR-21 is being gradually more and more recognized as a molecule regulating bone tissue homeostasis. However, its function is not fully understood due to the dual role of miR-21 on bone-forming and bone-resorbing cells. In this study, we investigated the impact of miR-21 inhibition on pre-osteoblastic cells differentiation and paracrine signaling towards pre-osteoclasts using indirect co-culture model of mouse pre-osteoblast (MC3T3) and pre-osteoclast (4B12) cell lines. The inhibition of miR-21 in MC3T3 cells (MC3T3inh21) modulated expression of genes encoding osteogenic markers including collagen type I (Coll-1), osteocalcin (Ocl), osteopontin (Opn), and runt-related transcription factor 2 (Runx-2). Inhibition of miR-21 in osteogenic cultures of MC3T3 also inflected the synthesis of OPN protein which is essential for proper mineralization of extracellular matrix (ECM) and anchoring osteoclasts to the bones. Furthermore, it was shown that in osteoblasts miR-21 regulates expression of factors that are vital for survival of pre-osteoclast, such as receptor activator of nuclear factor κB ligand (RANKL). The pre-osteoclast cultured with MC3T3inh21 cells was characterized by lowered expression of several markers associated with osteoclasts’ differentiation, foremost tartrate-resistant acid phosphatase (Trap) but also receptor activator of nuclear factor-κB ligand (Rank), cathepsin K (Ctsk), carbonic anhydrase II (CaII), and matrix metalloproteinase (Mmp-9). Collectively, our data indicate that the inhibition of miR-21 in MC3T3 cells impairs the differentiation and ECM mineralization as well as influences paracrine signaling leading to decreased viability of pre-osteoclasts.

scholarly journals Anti-Müllerian Hormone Negatively Regulates Osteoclast Differentiation by Suppressing the Receptor Activator of Nuclear Factor-κB Ligand Pathway

2021 ◽  
Vol 28 (3) ◽  
pp. 223-230
Author(s):  
Jung Ha Kim ◽  
Yong Ryoul Yang ◽  
Ki-Sun Kwon ◽  
Nacksung Kim
Keyword(s):  
Osteoblast Differentiation ◽  
Bone Cells ◽  
Osteoclast Differentiation ◽  
Nuclear Factor Κb ◽  
Bone Morphogenetic Protein 2 ◽  
Tartrate Resistant Acid Phosphatase ◽  
Nuclear Factor ◽  
Bone Homeostasis ◽  
Alizarin Red ◽  
Receptor Activator

Background: Multiple members of the transforming growth factor-β (TGF-β) superfamily have well-established roles in bone homeostasis. Anti-Müllerian hormone (AMH) is a member of TGF-β superfamily of glycoproteins that is responsible for the regression of fetal Müllerian ducts and the transcription inhibition of gonadal steroidogenic enzymes. However, the involvement of AMH in bone remodeling is unknown. Therefore, we investigated whether AMH has an effect on bone cells as other TGF-β superfamily members do.Methods: To identify the roles of AMH in bone cells, we administered AMH during osteoblast and osteoclast differentiation, cultured the cells, and then stained the cultured cells with Alizarin red and tartrate-resistant acid phosphatase, respectively. We analyzed the expression of osteoblast- or osteoclast-related genes using real-time polymerase chain reaction and western blot.Results: AMH does not affect bone morphogenetic protein 2-mediated osteoblast differentiation but inhibits receptor activator of nuclear factor-κB (NF-κB) ligand-induced osteoclast differentiation. The inhibitory effect of AMH on osteoclast differentiation is mediated by IκB-NF-κB signaling.Conclusions: AMH negatively regulates osteoclast differentiation without affecting osteoblast differentiation.

scholarly journals Osteoprotegerin Expressed by Osteoclasts

2014 ◽  
Vol 93 (11) ◽  
pp. 1116-1123 ◽  
Author(s):  
J.H. Kang ◽  
H.M. Ko ◽  
J.S. Moon ◽  
H.I. Yoo ◽  
J.Y. Jung ◽  
...  
Keyword(s):  
Late Phase ◽  
Nuclear Factor Κb ◽  
Tunel Staining ◽  
Tartrate Resistant Acid Phosphatase ◽  
Mouse Bone Marrow ◽  
Nuclear Factor ◽  
Chromosomal Dna ◽  
Receptor Activator ◽  
Bone Resorbing Activity

Osteoprotegerin (OPG) is secreted by stromal and osteoblastic lineage cells and inhibits osteoclastogenesis by preventing the interaction of receptor activator of nuclear factor-κB ligand (RANKL) with receptor activator of nuclear factor-κB (RANK). In this study, the expression of OPG in osteoclasts themselves and its biological functions during osteoclastogenesis were investigated for the first time. OPG expression in vivo in the developing rat maxilla was examined by immunofluorescence analysis. OPG expression in osteoclasts during in vitro osteoclastogenesis was determined by reverse-transcription polymerase chain-reaction (RT-PCR), Western blot, and immunofluorescence staining. We determined the function of OPG produced by osteoclasts during osteoclastogenesis by silencing the OPG gene. The effects of OPG on bone-resorbing activity and apoptosis of mature osteoclasts were examined by the assay of resorptive pit formation on calcium-phosphate-coated plate and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) staining, respectively. In the immunofluorescence findings, strong immunoreactivities were unexpectedly seen in multinucleated tartrate-resistant acid phosphatase (TRAP)-positive osteoclasts around the growing and erupting tooth germs in the rat alveolar bone. In vitro, OPG expression was significantly increased during the differentiation of osteoclasts from mouse bone-marrow-derived cells treated with a combination of macrophage colony-stimulating factor (M-CSF) and RANKL. Interestingly, it was found that OPG small interfering (si)RNA treatment during osteoclastogenesis enhanced the sizes of osteoclasts, but attenuated their bone-resorbing activity. Also, the increased chromosomal DNA fragmentation and caspase-3 activity in the late phase of osteoclastogenesis were found to be decreased by treatment with OPG siRNA. Furthermore, effects of OPG siRNA treatment on osteoclastogenesis and bone-resorbing activity were recovered by the treatment of exogenous OPG. These results suggest that OPG, expressed by the osteoclasts themselves, may play an auto-regulatory role in the late phase of osteoclastogenesis through the induction of apoptosis.

scholarly journals Spi-C positively regulates RANKL-mediated osteoclast differentiation and function

2020 ◽  
Vol 52 (4) ◽  
pp. 691-701 ◽  
Author(s):  
Eun Mi Go ◽  
Ju Hee Oh ◽  
Jin Hee Park ◽  
Soo Young Lee ◽  
Na Kyung Lee
Keyword(s):  
Transmembrane Protein ◽  
Osteoclast Differentiation ◽  
Nuclear Factor Κb ◽  
Mitogen Activated Protein Kinase ◽  
Tartrate Resistant Acid Phosphatase ◽  
Nuclear Factor ◽  
Activated T Cells ◽  
Specific Domain ◽  
Receptor Activator ◽  
And Function

Abstract Spi-C is an SPI-group erythroblast transformation-specific domain transcription factor expressed during B-cell development. Here, we report that Spi-C is a novel receptor activator of nuclear factor-κB ligand (RANKL)-inducible protein that positively regulates RANKL-mediated osteoclast differentiation and function. Knockdown of Spi-C decreased the expression of RANKL-induced nuclear factor of activated T-cells, cytoplasmic 1, receptor activator of nuclear factor-κB (RANK), and tartrate-resistant acid phosphatase (TRAP), resulting in a marked decrease in the number of TRAP-positive multinucleated cells. Spi-C-transduced bone marrow-derived monocytes/macrophages (BMMs) displayed a significant increase in osteoclast formation in the presence of RANKL. In addition, Spi-C-depleted cells failed to show actin ring formation or bone resorption owing to a marked reduction in the expression of RANKL-mediated dendritic cell-specific transmembrane protein and the d2 isoform of vacuolar (H+) ATPase V0 domain, which are known osteoclast fusion-related genes. Interestingly, RANKL stimulation induced the translocation of Spi-C from the cytoplasm into the nucleus during osteoclastogenesis, which was specifically blocked by inhibitors of p38 mitogen-activated protein kinase (MAPK) or PI3 kinase. Moreover, Spi-C depletion prevented RANKL-induced MAPK activation and the degradation of inhibitor of κB-α (IκBα) in BMMs. Collectively, these results suggest that Spi-C is a novel positive regulator that promotes both osteoclast differentiation and function.

scholarly journals Compounds Isolated from Wikstroemia taiwanensisRegulate Bone Remodeling by Modulating Osteoblast and Osteoclast Activities

2021 ◽  
Vol 12 ◽  
Author(s):  
Zuha Imtiyaz ◽  
Yi-Tzu Lin ◽  
Fang-Yu Liang ◽  
Wen-Fei Chiou ◽  
Mei-Hsien Lee
Keyword(s):  
Bone Remodeling ◽  
Nuclear Factor Κb ◽  
Tartrate Resistant Acid Phosphatase ◽  
Nuclear Factor ◽  
Treatment Of Osteoporosis ◽  
Human Osteoblasts ◽  
Osteoblast Activity ◽  
Mineral Deposition ◽  
Receptor Activator ◽  
Primary Human Osteoblasts

Bone remodeling, a dynamic process in which bone formation by osteoblast is preceded by bone resorption by osteoclast, is a vital physiological process for maintaining bone mass and strength, imbalances in which could precipitate osteoporosis. Due to the unilateral mechanism of the existing bone remodeling drugs, identifying compounds that could regulate the balance between osteoclast and osteoblast could improve the treatment of osteoporosis. Here, we show that compounds isolated from Wikstroemia taiwanensis modulate osteoclast and osteoblast activities. Specifically, astragalin (1) and kaempferol 3-O-β-D-apiofuranosyl-(1→6)-β-D-glucopyranoside (2), besides increasing mineral deposition, increased alkaline phosphatase activity (137.2% for 1 and 115.8% for 2) and ESR-α expression (112.8% for 1 and 122.5% for 2) in primary human osteoblasts. In contrast, compounds 1, 2, 3, and 5 inhibited tartrate-resistant acid phosphatase (TRAP) activity in receptor activator of nuclear factor-κB ligand-induced osteoclasts by 40.8, 17.1, 25.9, and 14.5% and also decreased the number of TRAP-positive cells by 51.6, 26.8, 20.5, and 18.6%, respectively. Our findings, therefore, showed that compounds isolated from W. taiwanensis could increase osteoblast activity while simultaneously decreasing osteoclast activity, and hence, warrant further evaluation for development as anti-osteoporosis agents.

scholarly journals Isofraxidin Inhibits Receptor Activator of Nuclear Factor-κB Ligand–Induced Osteoclastogenesis in Bone Marrow–Derived Macrophages Isolated from Sprague–Dawley Rats by Regulating NF-κB/NFATc1 and Akt/NFATc1 Signaling Pathways

2021 ◽  
Vol 30 ◽  
pp. 096368972199032
Author(s):  
Wei Wang ◽  
Bo Wang
Keyword(s):  
Bone Marrow ◽  
Signaling Pathways ◽  
Cathepsin K ◽  
Nuclear Factor Κb ◽  
Osteoclast Formation ◽  
Luciferase Reporter ◽  
Tartrate Resistant Acid Phosphatase ◽  
Nuclear Factor ◽  
Activated T Cells ◽  
Receptor Activator

Osteoporosis is a common bone disease that is characterized by decreased bone mass and fragility fractures. Isofraxidin is a hydroxy coumarin with several biological and pharmacological activities including an anti-osteoarthritis effect. However, the role of isofraxidin in osteoporosis has not yet been investigated. In the present study, we used receptor activator of nuclear factor-κB ligand (RANKL) to induce osteoclast formation in primary bone marrow macrophages (BMMs). Our results showed that RANKL treatment significantly increased tartrate-resistant acid phosphatase (TRAP) activity, as well as the expression of osteoclastogenesis-related markers including MMP-9, c-Src, and cathepsin K at both mRNA and protein levels; however, these effects were inhibited by isofraxidin in BMMs. In addition, luciferase reporter assay demonstrated that isofraxidin treatment suppressed the RANKL-induced an increase in nuclear factor of activated T-cells cytoplasmic 1 (NFATc1) transcriptional activity. Besides, the decreased expression level of IκBα and increased levels of p-p65, p-IκBα, and p-Akt in RANKL-induced BMMs were attenuated by isofraxidin. Moreover, NFATc1 overexpression rescued the anti-osteoclastogenic effect of isofraxidin with increased expression levels of MMP-9, c-Src, and cathepsin K. Taken together, these findings indicated that isofraxidin inhibited RANKL-induced osteoclast formation in BMMs via inhibiting the activation of NF-κB/NFATc1 and Akt/NFATc1 signaling pathways. Thus, isofraxidin might be a therapeutic agent for the treatment of osteoporosis.

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