Fig. 5
Functional downregulation of IL-17 in bone marrow cells of MRL/lpr mice suppressed recipient BMMSC-mediated osteoclastogenesis. a–d Osteoclast induction assay in bone marrow cell MRL/lpr (BMC-MRL/lpr) and recipient bone marrow mesenchymal stem cell (BMMSC) co-culture. a A schema of osteoclast induction in a co-culture system. BMC-MRL/lpr were pretreated with or without mouse interleukin-17 siRNA (IL-17 siRNA) and the control siRNA (Cont siRNA). Some BMCs were co-cultured with recipient BMMSCs under the stimulation with 1α, 25-(OH)2 vitamin D3 (VD3) and prostaglandin E2 (PGE2) in the presence of anti-mouse IL-17 antibody (Anti-IL-17 Ab) or control antibody for anti-mouse IL-17 antibody (Cont Ab). b Expression of IL-17 in BMC-MRL/lpr pretreated with IL-17 siRNA and Cont siRNA by Western blotting. c, d Osteoclast induction assay by tartrate-resistant acid phosphate (TRAP) staining. c Effects of IL-17 siRNA. d Effects of Anti-IL-17 Ab. e–g Direct osteoclast induction assay of recipient BMCs. e A schema of a direct osteoclast induction in a receptor activator for nuclear factor κB ligand and macrophage-colony stimulating factor (RANKL + M-CSF) system. Recipient BMCs were pretreated with or without IL-17 siRNA and Cont siRNA and cultured under a stimulation of M-CSF and RANKL. Some BMCs were cultured in the presence of Anti-IL-17 Ab or Cont Ab. f, g Osteoclast induction assay by TRAP staining. f Effects of IL-17 siRNA. g Effects of Anti-IL-17 Ab. n = 5 for all groups. Values are shown as means ± SD. *P < 0.05. c ¶ P < 0.05, ¶¶¶ P < 0.005, versus co-culture of Cont siRNA-treated BMC-MRL/lpr and MSC-MRL/lpr. # P < 0.05, versus co-culture of IL-17 siRNA-treated BMC-MRL/lpr and MSC-MRL/lpr co-culture. d ¶ P < 0.05, ¶¶ P < 0.01, ¶¶¶ P < 0.005, versus co-culture of BMC-MRL/lpr and MSC-WT in the presence of Cont Ab. # P < 0.05, versus co-culture of BMC-MRL/lpr and MSC-MRL/lpr in the presence of Anti-IL-17 Ab. MNC multinucleated cell; MSC mesenchymal stem cell; SHED stem cells from exfoliated deciduous teeth