Abstract: Objective The aim of this study was to investigate the effect of Ca²⁺/calmodulin-dependent kinase II(CaMKII)γ RNA interference on the expression of nuclear factor of activated T-cells cytoplasmic 1(NFATc1),tyrosine kinase(c-Src)and tartrate resistant acid phosphatase(TRAP)genes,and its role and molecular mechanism in osteoclast differentiation.Methods The CaMKII γ RNA interference vector was constructed by lentivirus and transfected into RAW264.7 cells.The experiment was divided into three groups:A,B and C,which were the control group,negative vector group and interference vector group.After transfection for 12 hours,osteoclasts induced by 50 ng/mL RANKL and the cells were harvested after induction for 5 days.Real-time quantitative PCR,Western blot and immunofluorescence were used to detect the expression of NFATc1,TRAP and c-Src genes in three groups.Results The mRNA levels of NFATc1,TRAP and c-Src in the group C decreased by 49.86%,43.65% and 53.57%,respectively(P＜0.001),and the protein levels decreased by 54.22%,46.75% and 45.86%,respectively(P＜0.001).There was no significant difference between the A and the B groups(P＞0.05).The fluorescence intensity of the above genes in the group C was significantly weaker than that in the A and B groups,and the formation of osteoclasts was significantly less than that in the A and B groups.Conclusion CaMKIIγ RNA interference significantly inhibited the expression of NFATc1,TRAP and c-Src genes,suggesting that CaMKIIγ plays a key regulatory role in osteoclast differentiation.

Key words: Calmodulin-dependent kinase IIγ, RNA interference, Nuclear factor of activated T-cells cytoplasmic 1, Cell-sarcoma receptor coactivator, Tartrate resistant acid phosphatase