RM-1 cell inoculation increases CXCR2 mRNA and protein expression in the spinal cord. (A) Real-time PCR results show the increase of CXCR2 mRNA expression in the spinal cord. CXCR2 mRNA was increased from 7 days to 21 days after inoculation. *P <0.05 vs. sham. n = 4 mice per group. (B) Western blot shows time course of CXCR2 protein expression in the spinal cord after inoculation (B). n = 3 mice per group. (C, D) Immunostaining shows the CXCR2 expression in the spinal cord in sham (C) and inoculated (D) animals. CXCR2-IR was increased at 7 days after inoculation. (E-G) Double staining shows CXCR2 was colocalized with neuronal marker NeuN. H, I. SB2205002 attenuated RM-1 cell inoculation-induced mechanical allodynia (H) and heat hyperalgesia (I). *P <0.05; **P <0.01; ***P <0.001 vs. vehicle.