Figure 4
Reduced TRPV1 and CAMKII expression, as well as decreased ERK phosphorylation, in the spinal dorsal horn following TRPV1 siRNA administration. Western blots showing the reduced expression of the TRPV1 protein in the spinal dorsal horn 24 hours after the intrathecal injection of the TRPV1 siRNA (5 μg/15 μl) once daily for 2 days, in both naive (A) and CCI (C) rats. (B,D) Bar chart depicting the level of TRPV1 protein relative to that in the group administered PEI alone; the level of TRPV1 in the spinal dorsal horn was significantly reduced. (E) Western blots showing the reduced expression of CAMKII following the intrathecal injection of the TRPV1 siRNA compared to the results in the CCI + PEI group. (F) Bar chart presenting the protein content relative to the CCI + PEI group; the CAMKII level was significantly reduced. (G) Western blots showing the reduced level of phosphorylated ERK2 following the intrathecal injection of the TRPV1 siRNA in comparison to the results in the CCI + PEI group. (H) Bar chart depicting the protein content relative to the CCI + PEI group; the level of phosphorylated ERK2 was significantly reduced in the CCI + siRNA group. Tubulin or GAPDH served as the loading control and was run on the same blot. TRPV1 levels were significantly reduced in the siRNA group compared with those in the PEI group in naive rats. **P = 0.001 compared with those in the PEI group (ANOVA, n = 5 rats per group). TRPV1 levels were significantly reduced in the CCI + siRNA group compared with those in the CCI + PEI group in CCI rats. **P = 0.003 compared with those in the CCI + PEI group (t-test, n = 4 rats per group). The level of CAMKII in the ipsilateral spinal dorsal horn of the CCI + siRNA group was significantly lower than that in the CCI + PEI group. *P = 0.026 compared with that in the CCI + PEI group (t-test, n = 3 rats per group). The level of phosphorylated ERK2 in the ipsilateral spinal dorsal horn of the CCI + RNAi group was significantly lower than that of the CCI + PEI group. **P = 0.002 compared with that in the CCI + PEI group (Mann-Whitney U test, n = 6 rats per group). Error bars represent the SEM. PEI: polyethylenimine; CCI: chronic constriction injury.
