Fig. 6

IL13Rα2 silencing reverses Chi3l1-promoting osteoclastogenesis and the activation of RANKL-induced MAPK/AKT pathway. A IL13Rα2 siRNA or NC-siRNA was transfected into BMMs, and after 48 hours, M-CSF and RANKL were used to treat BMMs with or without 500 ng/ml Chi3l1 recombinant protein. TRAP staining revealed that IL13Rα2 silencing inhibited the formation of mature multinucleated osteoclasts, which was increased by Chi3l1 recombinant protein and RANKL. B PCR analysis also showed that IL13Rα2 silencing downregulated the mRNA expression of the osteoclast differentiation-related genes that were promoted by Chi3l1 recombinant protein and RANKL. C After silencing IL13Rα2 expression in BMMs with siRNA for 48 h, BMMs were induced with RANKL for 10 and 20 minutes with or without 500 ng/ml Chi3l1 recombinant protein. The activation of MAPK (ERK/P38/JNK) and AKT signaling pathways was analyzed by western blot. D Quantitative densitometric analysis was performed to normalize p-AKT, p-ERK, p-P38, p-JNK, and p-P65 expressions as shown in (C). **P < 0.01. Results are presented as means ± SD