Development of non-traumatic osteonecrosis of the femoral head requires toll-like receptor 7 and 9 stimulations and is boosted by repression on nuclear factor kappa B in rats

Okazaki, Shunichiro; Nagoya, Satoshi; Matsumoto, Hiroshi; Mizuo, Keisuke; Sasaki, Mikito; Watanabe, Satoshi; Yamashita, Toshihiko; Inoue, Hiromasa

dose-dependent manner. In the groups co-administered 5 or 10 mg/kg BAY11-7082, no ONFH was observed after MPSL treatment. The incidence of ONFH in the group co-administered 5 mg/kg BAY11-7082 was significantly less than that in the Imiquimod þ MPSL group (P ¼ 0.01; Fisher's exact test). However, 1 of 10 rats died within 7 days after the administration of 1, 3, or 5 mg/kg BAY11-7082, and 3 of 6 rats died within 7 days after the administration of 10 mg/kg BAY11-7082. Owing to the high mortality observed in the BAY11-7082 group, no further experiments were performed using these rats. Figure 4 shows the activity of NF-kB and IRF7 in the liver at 24 h after MPSL treatment in Imiquimod þ MPSL (n ¼ 8)