Fig. 3

Heme induces the expression of TLR4 in CD11b-positive cells in the spinal cords. a At 1 day after the injections of saline, packed RBCs, lysed RBCs, or heme solution into the naïve spinal cord, sagittal sections were prepared. IHC staining around the injection sites showed the association between the expression of CD11b and TLR4. The right images are magnifications of the boxed area in merged images. b Quantification of the ratio of CD11b and TLR4 double-positive cells to CD11b single-positive cells of a (n = 6 in each group). Both Lysed RBCs and heme solution significantly upregulated the expression of TLR4 in CD11b-positive cells. Scale bars, 100 μm (a) and 40 μm in magnification. *p < 0.05, Dunnett’s test in comparison to sham-injected (laminectomy only) spinal cord (b). Error bars indicate the SEM