Fig. 2: Nuclear HDAC4 alters the expression of pain-relevant genes in vivo and reduces hypersensitivity in persistent but not acute inflammatory pain models.
From: Organic anion transporter 1 is an HDAC4-regulated mediator of nociceptive hypersensitivity in mice
a Schema of the rAAVs used. b Images of dorsal horn from spinal cord sections L3–5 following intraspinal injections of rAAV-HDAC4 wt or -HDAC4 3SA and intraplantar CFA injection. Constructs (green), Hoechst (blue, nuclei). Scale bar is 100 µm in the upper panels and 10 µm in the lower panels. c Images of dorsal sections of spinal cord L3–5, immunostained for acetylated histone H3-Lys9 (AcH3), intra-spinally injected as indicated, followed by injections of CFA or saline for 24 h. Scale bar is 300 µm. d Relative fluorescence intensities of the nuclear AcH3 signal in neurons of the dorsal horn following intraspinal rAAV delivery and intraplantar injections as in (c), normalized to contralateral (saline) (n = 3). e QRT-PCR analysis of Ptgs2 in lumbar L3–5 spinal cord segments 24 h after injections, in mice expressing indicated constructs (n = 3). Values were normalized to rAAV-LacZ saline-injected mice. f Paw withdrawal latency to a radiant heat light source. g Mechanical sensitivity following CFA injection. h 40% response threshold to mechanical force via von Frey filaments. i Stimulus intensity-response frequency curve for plantar von Frey mechanical stimulation for the same cohort of mice shown in (f–h) 24 h after CFA injection. j Response frequency to light touch (0.07 g filament) over time (LacZ n = 10, HDAC4 wt n = 11, HDAC4 3SA n = 9, f–j). k Cumulative durations of acute nocifensive behaviors evoked by capsaicin (n = 8). l, m Cumulative durations of nocifensive behaviors evoked by formalin. Bar graphs in m represent the sum of all nocifensive behaviors in the early (Phase I) and late (Phase II) phases, and panel l shows the response curves over time (LacZ, HDAC4 3SA n = 8; HDAC4 wt n = 7). Statistically significant differences were determined by one-way ANOVA followed by Dunnett’s post hoc test (d, F(2,6) = 0.8689697) or Tukey’s test (k, F(2,21) = 1.220); two-way ANOVA followed by Dunnett’s post hoc test (e; F(1,11) = 44.47) or two-way ANOVA with repeated measures followed by Dunnett’s post hoc test for comparisons to basal values and Tukey’s post hoc test for comparisons between conditions (f, F(8,216) = 83.08 F (2,27) = 0.9383; g, F(8,216) = 66.30 F(2,27) = 10.47; h, F(8, 216) = 49.47 F(2,27) = 17.48; i, F(5,135) = 88.67 F(2,27) = 24.19; j, F(8,216) = 37.44 F(2,27) = 16.61; l, F(11,220) = 15.24 F(2,20) = 17.70; m, F(1,20) = 243.6 F(2,20) = 17.25). ****p < 0.0001; ***p < 0.001; **p < 0.01; *p < 0.05; #p < 0.0001. Asterisks (*) refer to statistical comparisons between conditions and hashtags (#) to comparisons relative to basal values within each condition. Each point represents the mean value derived from one mouse. Graphs represent mean ± SEM. See also Supplementary Fig. 3.
