Cation channel blocker-ruthenium red promoted osteoclastogenesis

Objective To investigate the effects of ruthenium red on the differentiation of osteoclasts and relative mechanism.Methods Receptor activator of nuclear factor-κB ligand (RANKL) was used to stimulate osteoclast differentiation.Osteoclast differentiation was assessed by tartrate-resistant acid phosphatase (TRAP) staining and the TRAP-positive cells were counted after exposure to 50 μg/L RANKL for 6 days.Tartrate-resistant acid phosphatase kit was used to evaluate TRAP activity.The expression of osteoclast specific genes [TRAP,Capthesin K (CK),matrix metalloproteinase (MMP)-9] mRNA expression was detected by using real-time quantitative reverse transcription-polymerase chain reaction (RT-qPCR).The receptor activator of nuclear factor κb(RANK) mRNA and protein expression was also detected.Resuits Ruthenium red promoted RANKL-stimulated osteoclast differentiation in Raw246.7 cell culture,as manifested by the increase of TRAP positive multinucleated cells and TRAP activity.In control group the TRAP A was 0.33 ± 0.04,and that in ruthenium red group was 0.43 ± 0.03.Ruthenium also up-regulated TRAP,CK,MMP-9 and RANK mRNA expression,and increased RANK protein expression.The difference between two groups was significant (P ＜ 0.05).Conclusion Ruthenium red promoted osteoclast differentiation,which might by related to RANK-RANKL axis. Key words: Ruthenium red ;  Osteoclastst;  Differentiation