Effects of IRAK-4 gene silencing by siRNA on the mitogen-activated protein kinase signaling pathway in osteoblast-like cells

Background: The molecular mechanism for osteolysis around prostheses remains unclear. Artificial joint loosening is typified by osteolytic resorption. Interleukin-1 affects bone resorption via the MAPK signaling pathway. The aim of this study was to observe the effects of siRNA-silenced expression of interleukin-1 receptor-associated kinase-4 (IRAK-4) gene on the mitogen-activated protein kinase (MAPK) signaling transduction pathway in human osteoblast-like cells MG63, and to provide experimental evidence for the prevention and treatment of osteolysis around prostheses after artificial joint replacement. Methods: IRAK-4-siRNA was transfected into MG63 cells by using Lipofectamine 2000 as the vector. The cells were divided into a blank group, a control group and a silencing group, which were not transfected, transfected with scrambled siRNA and with specific IRAK-4-siRNA respectively. The protein expressions of extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (c-JNK) and p38MAPK in target cells were detected by Western blot. Results: Compared with the control group, the IRAK-4 mRNA and protein expression levels of the silencing group were significantly lower (P< 0.05). After IRAK-4 expression was down-regulated, the expressions of c-JNK1/2 p46, ERK1/2 and p-p38 MAPK were also down-regulated by 62%, 64% and 68% respectively (P<0.05). Conclusion: Silencing IRAK-4 gene expression with siRNA inhibited the expressions of ERK, c-JNK and p38 MAPK in human osteoblast-like cells MG63.