Spinal nerve injury-induced expression of CCL2/MCP-1 and CCL3/MIP-1α in DRGs is reduced in TLR2 knock-out mice. (A and B) DRG tissues were obtained from ipsilateral L5 spinal nerve of un-injured naïve mice (control; n = 5), injured WT mice (WT; n = 5), and injured TLR2 knock-out mice (TLR2; n = 5) at 6, 12, and 24 h post-injury. Total RNA was isolated from pooled DRG tissues of each group, and CCL2/MCP-1 and CCL3/MIP-1α mRNA expression was measured by real-time RT-PCR. The expression level of each gene was normalized to the level of the GAPDH gene and presented as fold-induction compared with uninjured naïve mice. The experiments were independently performed twice and the data presented as mean ± SEM. (#, p < 0.05; ##, p < 0.01; naïve (control) mice vs. 6, 24, and 48 h post-injury; *, p < 0.05; **, p < 0.01, WT vs. TLR2 knock-out mice).