Fig. 5

Trichostatin A (TSA) protection of osteoarthritis (OA) requires nuclear factor (erythroid-derived 2)-like 2 (Nrf2). a Wild-type (WT) and Nrf2-knockout (Nrf2-KO) mice were subjected to monosodium iodoacetate (MIA)-induced OA or MIA-induced OA with or without TSA treatment (n = 10 in each group). Mouse joint sections were stained with Safranin O/Fast Green. Representative images are shown. Lower panels show amplifications of upper panel insets. Yellow arrows indicate the damage-affected cartilage areas. b Summed scores of femur and tibia damage in WT and Nrf2-KO mice with MIA-induced OA. *p < 0.05. c Maximum scores representing femur and tibia damage in WT and Nrf2-KO mice with MIA-induced OA. *p < 0.05. d WT and Nrf2-KO mice were subjected to destabilization of the medial meniscus (DMM)-induced OA or to DMM-induced OA with or without TSA treatment (n = 10 in each group). Mouse joint tissue sections were stained with Safranin O/Fast Green. Representative images are shown. Lower panels show amplifications of upper panel insets. Yellow arrows indicate the damage-affected cartilage areas. e Summed scores of femur and tibia damage in WT and Nrf2-KO mice with DMM-induced OA. *p < 0.05, **p < 0.01 compared with OA group. f Maximum scores of femur and tibia damage in WT and Nrf2-KO mice with DMM-induced OA. *p < 0.05. g Quantitative real-time polymerase chain reaction (qRT-PCR) analysis of matrix metalloproteinases MMP-1, MMP-3, and MMP-13 from joints of WT and Nrf2-KO mice with MIA-induced OA or TSA-treated MIA-induced OA. *p < 0.05, **p < 0.01 compared with MIA-OA mice. qRT-PCR analysis of HO-1 (h) and NQO1 (i) from joints of WT and Nrf2-KO mice with MIA-OA or TSA-treated OA. *p < 0.05, **p < 0.01 compared with MIA-OA mice