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BMC Musculoskeletal Disorders
Published in: BMC Musculoskeletal Disorders 1/2010

Open Access 01-12-2010 | Research article

Silencing Dkk1 expression rescues dexamethasone-induced suppression of primary human osteoblast differentiation

Authors: Joseph S Butler, Joseph M Queally, Brian M Devitt, David W Murray, Peter P Doran, John M O'Byrne

Published in: BMC Musculoskeletal Disorders | Issue 1/2010

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Abstract

Background

The Wnt/β-catenin pathway is a major signaling cascade in bone biology, playing a key role in bone development and remodeling. The objectives of this study were firstly, to determine the effects of dexamethasone exposure on Wnt/β-catenin signaling at an intracellular and transcriptional level, and secondly, to assess the phenotypic effects of silencing the Wnt antagonist, Dickkopf-1 (Dkk1) in the setting of dexamethasone exposure.

Methods

Primary human osteoblasts were exposed in vitro to 10-8 M dexamethasone over a 72 h time course. The phenotypic marker of osteoblast differentiation was analyzed was alkaline phosphatase activity. Intracellular β-catenin trafficking was assessed using immunoflourescence staining and TCF/LEF mediated transcription was analyzed using a Wnt luciferase reporter assay. Dkk1 expression was silenced using small interfering RNA (siRNA).

Results

Primary human osteoblasts exposed to dexamethasone displayed a significant reductions in alkaline phosphatase activity over a 72 h time course. Immunoflourescence analaysis of β-catenin localization demonstrated a significant reduction in intracytosolic and intranuclear β-catenin in response to dexamethasone exposure. These changes were associated with a reduction of TCF/LEF mediated transcription. Silencing Dkk1 expression in primary human osteoblasts exposed to dexamethasone resulted in an increase in alkaline phosphatase activity when compared to scrambled control.

Conclusions

Wnt/β-catenin signaling plays a key role in regulating glucocorticoid-induced osteoporosis in vitro. Silencing Dkk1 expression rescues dexamethasone-induced suppression of primary human osteoblast differentiation. Targeting of the Wnt/β-catenin signaling pathway offers an exciting opportunity to develop novel anabolic bone agents to treat osteoporosis and disorders of bone mass.
Appendix
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Literature
1.
NIH Consensus Development Panel on Osteoporosis Prevention Diagnosis Therapy: Osteoporosis prevention, diagnosis, and therapy. JAMA. 2001, 285 (6): 785-95. 10.1001/jama.285.6.785.CrossRef
2.
Hurson CJ, Butler JS, Keating DT, Murray DW, Sadlier DM, O'Byrne JM, Doran PP: Gene expression analysis in human osteoblasts exposed to dexamethasone identifies altered developmental pathways as putative drivers of osteoporosis. BMC Musculoskelet Disord. 2007, 8: 12-10.1186/1471-2474-8-12.CrossRefPubMedPubMedCentral
3.
Moon RT, Bowerman B, Boutros M, Perrimon N: The promise and perils of Wnt signaling through beta-catenin. Science. 2002, 296: 1644-6. 10.1126/science.1071549.CrossRefPubMed
4.
Pandur P, Maurus D, Kuhl M: Increasingly complex: new players enter the Wnt signaling network. Bioessays. 2002, 24 (10): 881-4. 10.1002/bies.10164.CrossRefPubMed
5.
Logan CY, Nusse R: The Wnt signaling pathway in development and disease. Annu Rev Cell Dev Biol. 2004, 20: 781-810. 10.1146/annurev.cellbio.20.010403.113126.CrossRefPubMed
6.
Miller JR: The Wnts. Genome Biol. 2002, 3 (1): REVIEWS3001-Epub 2001 Dec 28PubMed
7.
Gong YQ, Slee RB, Fukai N, Rawadi G, Roman-Roman S, Reginato AM, et al.: LDL receptor-related protein 5 (LRP5) affects bone accrual and eye development. Cell. 2001, 107: 513-23. 10.1016/S0092-8674(01)00571-2.CrossRefPubMed
8.
Gong YQ, Vikkula M, Boon L, Liu J, Beighton P, Ramesar R, et al.: Osteoporosis-pseudoglioma syndrome, a disorder affecting skeletal strength and vision, is assigned to chromosome region 11q12-13. Am J Hum Genet. 1996, 59: 146-51.PubMedPubMedCentral
9.
Boyden LM, Mao JH, Belsky J, Mitzner L, Farhi A, Mitnick MA, et al.: High bone density due to a mutation in LDL-receptor-related protein 5. N Engl J Med. 2002, 346: 1513-21. 10.1056/NEJMoa013444.CrossRefPubMed
10.
Little RD, Carulli JP, Del Mastro RG, Dupuis J, Osborne M, Folz C, et al.: A mutation in the LDL receptor-related protein 5 gene results in the autosomal dominant high-bone-mass trait. Am J Hum Genet. 2002, 70: 11-9. 10.1086/338450.CrossRefPubMed
11.
Van Wesenbeeck L, Cleiren E, Gram J, Beals RK, Benichou O, Scopelliti D, et al.: Six novel missense mutations in the LDL receptor-related protein 5 (LRP5) gene in different conditions with an increased bone density. Am J Hum Genet. 2003, 72: 763-71. 10.1086/368277.CrossRefPubMedPubMedCentral
12.
Moon RT, Kohn AD, De Ferrari GV, Kaykas A: WNT and beta-catenin signalling: diseases and therapies. Nat Rev Genet. 2004, 5 (9): 691-701. 10.1038/nrg1427.CrossRefPubMed
13.
14.
Baron R, Rawadi G, Roman-Roman S: Wnt signaling: a key regulator of bone mass. Curr Top Dev Biol. 2006, 76: 103-27. 10.1016/S0070-2153(06)76004-5.CrossRefPubMed
15.
Westendorf JJ, Kahler RA, Schroeder TM: Wnt signaling in osteoblasts and bone diseases. Gene. 2004, 341: 19-39. 10.1016/j.gene.2004.06.044.CrossRefPubMed
16.
Hoeppner LH, Secreto FJ, Westendorf JJ: Wnt signaling as a therapeutic target for bone diseases. Expert Opin Ther Targets. 2009, 13 (4): 485-96. 10.1517/14728220902841961.CrossRefPubMedPubMedCentral
17.
Rawadi G: Wnt signaling and potential applications in bone diseases. Curr Drug Targets. 2008, 9 (7): 581-90. 10.2174/138945008784911778.CrossRefPubMed
18.
Johnson ML, Harnish K, Nusse R, Van Hul W: LRP5 and Wnt signaling: a union made for bone. J Bone Miner Res. 2004, 19 (11): 1749-57. 10.1359/JBMR.040816. Epub 2004 Aug 23CrossRefPubMed
19.
Balemans W, Ebeling M, Patel N, Van Hul E, Olson P, Dioszegi M, et al.: Increased bone density in sclerosteosis is due to the deficiency of a novel secreted protein (SOST). Hum Mol Genet. 2001, 10 (5): 537-43. 10.1093/hmg/10.5.537.CrossRefPubMed
20.
Staehling-Hampton K, Proll S, Paeper BW, Zhao L, Charmley P, et al.: A 52-kb deletion in the SOST-MEOX1 intergenic region on 17q12-q21 is associated with van Buchem disease in the Dutch population. Am J Genet. 2002, 110 (2): 144-52. 10.1002/ajmg.10401.CrossRef
21.
Bafico A, Liu GZ, Yaniv A, Gazit A, Aaronson SA: Novel mechanism of Wnt signalling inhibition mediated by Dickkopf-1 interaction with LRP6/Arrow. Nat Cell Biol. 2001, 3: 683-6. 10.1038/35083081.CrossRefPubMed
22.
Davidson G, Mao BY, Barrantes ID, Niehrs C: Kremen proteins interact with Dickkopf1 to regulate anteroposterior CNS patterning. Development. 2002, 129: 5587-96. 10.1242/dev.00154.CrossRefPubMed
23.
Gregory CA, Singh H, Perry AS, Prockop DJ: The Wnt signaling inhibitor dickkopf-1 is required for reentry into the cell cycle of human adult stem cells from bone marrow. J Biol Chem. 2003, 278: 28067-78. 10.1074/jbc.M300373200.CrossRefPubMed
24.
Chu EY, Hens J, Andl T, Kairo A, Yamaguchi TP, Brisken C, et al.: Canonical WNT signaling promotes mammary placode development and is essential for initiation of mammary gland morphogenesis. Development. 2004, 131: 4819-29. 10.1242/dev.01347.CrossRefPubMed
25.
Kuhnert F, Davis CR, Wang HT, Chu P, Lee M, Yuan J, et al.: Essential requirement for Wnt signaling in proliferation of adult small intestine and colon revealed by adenoviral expression of Dickkopf-1. Proc Natl Acad Sci USA. 2004, 101: 266-71. 10.1073/pnas.2536800100.CrossRefPubMed
26.
Li XF, Liu P, Liu WZ, Maye P, Zhang JH, Zhang YH, et al.: Dkk2 has a role in terminal osteoblast differentiation and mineralized matrix formation. Nat Genet. 2005, 37: 945-52. 10.1038/ng1614.CrossRefPubMed
27.
Tian E, Zhan FH, Walker R, Rasmussen E, Ma YP, Barlogie B, et al.: The role of the Wnt-signaling antagonist DKK1 in the development of osteolytic lesions in multiple myeloma. N Engl J Med. 2003, 349: 2483-94. 10.1056/NEJMoa030847.CrossRefPubMed
28.
Li J, Sarosi I, Cattley RC, Pretorius J, Asuncion F, Grisanti M, et al.: Dkk1-mediated inhibition of Wnt signaling in bone results in osteopenia. Bone. 2006, 39 (4): 754-66. 10.1016/j.bone.2006.03.017. Epub 2006 May 26CrossRefPubMed
29.
Morvan F, Boulukos K, Clément-Lacroix P, Roman Roman S, et al.: Deletion of a single allele of the Dkk1 gene leads to an increase in bone formation and bone mass. J Bone Miner Res. 2006, 21 (6): 934-45. 10.1359/jbmr.060311.CrossRefPubMed
30.
MacDonald BT, Joiner DM, Oyserman SM, Sharma P, Goldstein SA: Bone mass is inversely proportional to Dkk1 levels in mice. Bone. 2007, 41 (3): 331-9. 10.1016/j.bone.2007.05.009. Epub 2007 Jun 5CrossRefPubMedPubMedCentral
31.
Wang FS, Ko JY, Yeh DW, Ke HC, Wu HL: Modulation of Dickkopf-1 attenuates glucocorticoid induction of osteoblast apoptosis, adipocytic differentiation, and bone mass loss. Endocrinology. 2008, 149 (4): 1793-801. 10.1210/en.2007-0910. Epub 2008 Jan 3CrossRefPubMed
32.
Ohnaka K, Taniguchi H, Kawate H, Nawata H, Takayanagi R: Glucocorticoid enhances the expression of dickkopf-1 in human osteoblasts: novel mechanism of glucocorticoid-induced osteoporosis. Biochem Biophys Res Commun. 2004, 318 (1): 259-64. 10.1016/j.bbrc.2004.04.025.CrossRefPubMed
33.
Ohnaka K, Tanabe M, Kawate H, Nawata H, Takayanagi R: Glucocorticoid suppresses the canonical Wnt signal in cultured human osteoblasts. Biochem Biophys Res Commun. 2005, 329 (1): 177-81. 10.1016/j.bbrc.2005.01.117.CrossRefPubMed
Metadata
Title
Silencing Dkk1 expression rescues dexamethasone-induced suppression of primary human osteoblast differentiation
Authors
Joseph S Butler
Joseph M Queally
Brian M Devitt
David W Murray
Peter P Doran
John M O'Byrne
Publication date
01-12-2010
Publisher
BioMed Central
Published in
BMC Musculoskeletal Disorders / Issue 1/2010
Electronic ISSN: 1471-2474
DOI
https://doi.org/10.1186/1471-2474-11-210

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