Fig. 3.
Dorsal root ganglion PRDM1 knockdown increases the nociceptive response threshold in naive mice and attenuates chronic constriction injury–induced nociception development in mice. (A) A schematic map of the pain behavior assessment. (B and C) Levels of PRDM1 protein in ipsilateral lumbar 4 and lumbar 5 dorsal root ganglions on day 7 after chronic constriction injury in chronic constriction injury or naive mice injected with adeno-associated virus 5–Prdm1 short hairpin RNA or adeno-associated virus 5–control scrambled short hairpin RNA (Scram). Data are expressed as mean ± SD. *P < 0.05 and ***P < 0.001 versus the corresponding naive + Scram group, ###P < 0.001 versus the corresponding chronic constriction injury + Scram group. One-way ANOVA followed by post hoc Tukey test, F(3, 20) = 20.62, n = 6 per group. (D) Level of Prdm1 mRNA in ipsilateral lumbar 4 and lumbar 5 dorsal root ganglions on day 7 after chronic constriction injury in chronic constriction injury or naive mice injected with short hairpin RNA or Scram. Data are expressed as mean ± SD. *P < 0.05 versus the corresponding naive + Scram group. #P < 0.05 versus the corresponding chronic constriction injury + Scram group. One-way ANOVA followed by post hoc Tukey test, F(3, 20) = 11.75, n = 6 per group. (E through G) The effect of microinjection of short hairpin RNA or Scram into ipsilateral lumbar 4 and lumbar 5 dorsal root ganglions on paw withdrawal responses to mechanical (E), thermal (F), and cold (G) stimuli on the ipsilateral side at the indicated days before or after chronic constriction injury surgery in mice. Data are expressed as mean ± SD. *P < 0.05, **P < 0.01, and ***P < 0.001 versus the Scram group by two-way ANOVA followed by post hoc Bonferroni multiple comparison test, F(4, 70) = 8.32 (E), F(4, 70) = 4.52 (F), and F(4, 70) = 9.11 (G), n = 8 per group. (H and I) Percentage of the ipsilateral paw print area (H) and single stance (I) assessed by CatWalk analysis (% ipsilateral/contralateral). Data are expressed as mean ± SD. ***P < 0.001 versus the Scram group by two-way ANOVA followed by post hoc Bonferroni multiple comparison test, F(1, 7) = 17.85 (H) and F(1, 7) = 93.15 (I), n = 8 per group. (J) Combined paw print image. (K) Representative digitized paw prints and associated step cycles. PRDM1, positive regulatory domain I–binding factor 1.