Major histocompatibility complex class I (MHC I) and β2-microglobulin mRNA levels in the spinal cord of wild-type (WT) and C3H/HeJ Toll-like receptor (TLR)4 mutant mice after axotomy. (A) Western blot analysis of MHC I expression in the lumbar spinal cord of the contralateral and ipsilateral sides. MHC I was upregulated after lesion, with no difference between groups. β-Actin was used as sample loading control. UL = unlesioned; L = lesioned. (B) β2-Microglobulin mRNA level determined by reverse transcriptase PCR in the lumbar spinal cord of C3H/HePas WT and C3H/HeJ TLR4 mutant mice. (B) Graph showing β2-microglobulin mRNA upregulation after nerve injury, with no difference between groups.