Abstract: Objective To evaluate the expression level of miRNA-146a (miR-146a) in neuropathic pain of bilateral chronic constriction injury (bCCI) rat and the effect of miR-146a on its target gene IRAK1 and TRAF6, and to explore the regulatory mechanism of miR-146a in neuropathic pain. Methods 36 female rats were divided randomly into bCCI group in which 12 rats received bilateral chronic constriction surgery, sham group and na?ve group. Behavior test were performed on the day before surgery and on day 3,7 and 14 after surgery. L4-L6 dorsal root ganglions were harvested on day 14 after surgery. RT-qPCR was used to test the mRNA expression of miR-146a, IRAK1 and TRAF6. Western Blot was performed to explore the protein expression of IRAK1 and TRAF6. Results Pain-related behavioral test scores of bCCI rats were significantly decreased as compared to sham group and na?ve group rats at each time point after surgery (P<0.05). Compared with sham group and na?ve group, the expression of miRNA-146a was greatly decreased, whereas IRAK1 mRNA and TRAF6 mRNA were significant increased on day 14 after surgery in bCCI rat group. Western Blot result showed that IRAK1 and TRAF6 on protein level increased in DRG of bCCI rat on day 14 postoperatively (P<0.05). Conclusion Our research suggested that decreased expression of miR-146a in DRG of bCCI rats and miR-146a might contribute to neuropathic pain by up-regulating IRAK1 and TRAF6.

Key words: neuropathic pain, miR-146a, IRAK1, TRAF6