Open Access Open Badges Research article

Inhibition of osteoclastogenesis by RNA interference targeting RANK

Ruofan Ma1, Jie Xu1, Bin Dong1, Max Daniel Kauther2, Marcus Jäger3 and Christian Wedemeyer3*

Author Affiliations

1 Department of Orthopaedics, Sun Yat-sen Memorial Hospital of Sun Yat-sen University, 107 West Yan Jiang Road, PO Box 510120, Guangzhou, China

2 Department of Trauma Surgery, University of Duisburg-Essen, Hufelandstr. 55, 45122, Essen, Germany

3 Department of Orthopaedics, University of Duisburg-Essen, Hufelandstr. 55, 45122, Essen, Germany

For all author emails, please log on.

BMC Musculoskeletal Disorders 2012, 13:154  doi:10.1186/1471-2474-13-154

Published: 22 August 2012



Osteoclasts and osteoblasts regulate bone resorption and formation to allow bone remodeling and homeostasis. The balance between bone resorption and formation is disturbed by abnormal recruitment of osteoclasts. Osteoclast differentiation is dependent on the receptor activator of nuclear factor NF-kappa B (RANK) ligand (RANKL) as well as the macrophage colony-stimulating factor (M-CSF). The RANKL/RANK system and RANK signaling induce osteoclast formation mediated by various cytokines. The RANK/RANKL pathway has been primarily implicated in metabolic, degenerative and neoplastic bone disorders or osteolysis. The central role of RANK/RANKL interaction in osteoclastogenesis makes RANK an attractive target for potential therapies in treatment of osteolysis. The purpose of this study was to assess the effect of inhibition of RANK expression in mouse bone marrow macrophages on osteoclast differentiation and bone resorption.


Three pairs of short hairpin RNAs (shRNA) targeting RANK were designed and synthesized. The optimal shRNA was selected among three pairs of shRNAs by RANK expression analyzed by Western blot and Real-time PCR. We investigated suppression of osteoclastogenesis of mouse bone marrow macrophages (BMMs) using the optimal shRNA by targeting RANK.


Among the three shRANKs examined, shRANK-3 significantly suppressed [88.3%] the RANK expression (p < 0.01). shRANK-3 also brought about a marked inhibition of osteoclast formation and bone resorption as demonstrated by tartrate–resistant acid phosphatase (TRAP) staining and osteoclast resorption assay. The results of our study show that retrovirus-mediated shRANK-3 suppresses osteoclast differentiation and osteolysis of BMMs.


These findings suggest that retrovirus-mediated shRNA targeting RANK inhibits osteoclast differentiation and osteolysis. It may appear an attractive target for preventing osteolysis in humans with a potential clinical application.

RANK; Inhibition; RNA interference; Cell culture