Interactomics profiling of the negative regulatory function of carbon monoxide on RANKL-treated RAW 264.7 cells during osteoclastogenesis
1 Graduate Institute of Medical Science, National Defense Medical Center, Neihu 114, Taipei, Taiwan, Republic of China
2 Department of Orthopedics, Hualien Armed Force Hospital, Hualien 971, Taiwan, Republic of China
3 Department of Health, Hsin Chu General Hospital, Hsinchu 300, Taiwan, Republic of China
4 Department of Biology and Anatomy, National Defense Medical Center, Neihu 114, Taipei, Taiwan, Republic of China
5 Department of Orthopaedics, Tri-Service General Hospital, National Defense Medical Center, Neihu 114, Taipei, Taiwan, Republic of China
6 Department of Life Science, National Chung Cheng University, 168 University Road, Minhsiung, Chiayi 621, Republic of China
BMC Systems Biology 2014, 8:57 doi:10.1186/1752-0509-8-57Published: 18 May 2014
During osteoclastogenesis, the maturation of osteoclast (OC) progenitors is stimulated by the receptor activator of nuclear factor-κB ligand (RANKL). Excess OC production plays a critical role in the pathogenesis of inflammatory bone disorders. Conversely, the inhibition of abnormal OC proliferation reduces inflammation-induced bone loss. Low concentrations of carbon monoxide (CO) are known to decrease inflammation and OC-mediated bone erosion but the molecular mechanism is unknown.
To obtain insight into the biological function of CO, cultured RANKL-treated RAW 264.7 cells were used in an in vitro experimental model of osteoclastogenesis. The results showed that CO inhibited: 1) tartrate-resistant acid phosphatase (TRAP)-positive cell formation; 2) F-actin ring production; 3) c-fos pathway activation; 4) the expression of cathepsin K, TRAP, calcitonin receptor, and matrix metalloproteinase-9 mRNAs; 5) the expression of nuclear factor of activated T cells, cytoplasmic, calcineurin-dependent 1 in translation. Protein-protein interaction analysis predicted mitogen-activated protein kinase kinase kinase 4 as the controlling hub.
Low-concentrations of CO (250 ppm) may inhibit osteoclastogenesis. Data from STRING- and IPA-based interactome analyses suggested that the expression of proteins with the functions of signal transduction, enzymes, and epigenetic regulation are significantly altered by CO during RANKL-induced osteoclastogenesis. Our study provides the first interactome analysis of osteoclastogenesis, the results of which supported the negative regulation of OC differentiation by CO.