Nrf2 Activation Attenuates Chronic Constriction Injury-Induced Neuropathic Pain via Induction of PGC-1α-Mediated Mitochondrial Biogenesis in the Spinal Cord

Figure 4

Effect of the Nrf2 inhibitor on pain hypersensitivity and the spinal expression of Nrf2 in the nuclear extracts. (a, b) The analgesic effect of RTA-408 (10 μg, i.t.) in CCI mice was completely inhibited by the Nrf2 inhibitor trigonelline (Trig). Two-way ANOVA with repeated measures was performed, followed by the Bonferroni post hoc test (, , and compared with the sham+vehicle group, ^#, ^##, and ^### compared with the CCI+RTA+Trig group, per group). (c) The spinal expression of Nrf2 in the nuclear extracts was significantly increased following CCI. Representative blots and blot density (normalized to histone H3 loading control) are presented ( compared with the sham+vehicle group). RTA-408 administration further increased the spinal expression of Nrf2 in the nuclear extracts in the CCI group ( compared with the CCI+vehicle group, in each group), which was significantly inhibited by the preinjection of trigonelline. One-way ANOVA followed by Bonferroni analysis was used to test the differences among groups ( compared with the CCI+RTA-408 group, per group).

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