Fig. 3

HMGB1 activated TLR4 and RAGE in vitro, and SCI induced the expression of RAGE in macropgahes/microglia. The mRNA expression of TLR4 (a) and RAGE (b) was significantly increased in microglia at 24 h after 0.4 or 1 μg/ml HMGB1 treatment. (c–d) Double-staining of GFAP/TLR4 and quantification of TLR4-positive cell types at 5 dpi. Note that about 80% TLR4-positive cells were GFAP-positive, while 17% were Iba-1 positive. Scale bar = 50 μm. e Representative images of double-staining of RAGE and F4/80 in injured cord of saline- or glycyrrhizin-treated rats. Scale bar = 50 μm. f Quantification of the relative percentage of RAGE-positive cells in F4/80-positive cells. N = 4, *P < 0.05