Figure 5.

Intracellular signaling molecule mTOR mediated nociceptive effect of EGFR. The expression level of mTOR (a) or GS (c) was markedly reduced by treating with EGFR siRNA (Si, 250 nM) in in vitro DRG cell culture. N = 3 repeats (six wells from three rats) per treatment. **P < 0.01, ***P < 0.001 versus NC siRNA treatment by two-tailed unpaired Student’s t test. Intrathecal injection of EGFR siRNA (10 µM in 10 µl vehicle solution) blocked the increase of mTOR (b) or GS (d) induced by CCD and did not affect their basal expressions in sham group. The first injection was administered on day 3 post-CCD and once daily for four days. Ipsilateral L4/L5 DRGs were harvested on day 7 after surgery. N = 3 rats/time point. One-way ANOVA (effect vs. the treated groups) followed by post hoc Tukey test, *P < 0.05 versus the sham + Veh group. ##P < 0.01 versus the CCD + Veh group. CCD: chronic compression of DRG; DRG: dorsal root ganglion; GS: glutamine synthetase; mTOR: mammalian target of rapamycin; NC: negative control.