Fig 1.
The behavioral effects of RGFP966 (25 mg/kg) on WT and N171-82Q transgenic mice.
Panel A shows the effects of RGFP966 on the body weights of female and male WT and N171-82Q transgenic mice. Differences in drug- vs. vehicle-treated female mice were determined by Two-way ANOVA (***, F(1,122) = 5.6; P = 0.0002). Panel B shows rotarod performance of vehicle- and RGFP966-treated female and male N171-82Q transgenic mice. Two-way ANOVA revealed significant differences between drug- and vehicle-treated female transgenic mice (****, F(1,176) = 34.1; P<0.0001). (C) Effects of RGFP966 treatment on ambulatory distance and vertical counts in WT and N171-82Q transgenic mice over a 10 minute test period. Two-way ANOVA revealed significant differences between drug- and vehicle-treated N171-82Q transgenic mice in ambulatory distance (****, F(1,440) = 27.2; <0.0001), and vertical counts (****, F(1,450) = 23.5; P<0.0001). Additional measures of open field activity and the summary of effects of RGFP966 at different doses are shown in Table 1.
Table 1.
Summary of the HD phenotypes affected by RGFP966 treatment at different doses in N171-82Q transgenic mice.
Fig 2.
The effects of RGFP966 (25 mg/kg) on striatal volume in WT and N171-82Q transgenic mice.
Representative photomicrographs of the striatum at ~0.62 Bregma under each condition are shown on the left. Scale bar = 40 μm. Bar graphs show quantitation of striatal volume. The total area of the striatum was assessed using sections 125 μm apart spanning the striatum from ~bregma, 1.18 to 0.38 mm. One-way ANOVA (Dunnett’s post-test) revealed significant differences between vehicle-treated wild type and N171-82Q transgenic mice and also a significant difference between vehicle-treated and RGFP966-treated N171-82Q mice (*, P<0.05). Bars represent mean score ± SEM (n = 6 to 7 per group).
Fig 3.
Summary of cytokines array gene expression changes in striatum due to RGFP966 treatment.
A. Heatmap of expression values for 84 cytokine/chemokine genes showing two-way clustering of expression levels and treatment groups. Red denotes increased relative gene expression levels for the indicated groups, with green denoting decreased expression levels. B. Volcano plots of expression changes due to RGFP966 treatment showing three different comparisons, as indicated. Dotted line on y-axis denotes the significance cut-off of p-value<0.05, using one-way ANOVA. Dotted lines on x-axis denote a fold-change cut-off of > +/- 2.
Fig 4.
Real-time qPCR results showing altered expression of Mif and Il1b in striatum and cortex of RGFP966 treated WT and N171-82Q mice.
Groups of mice were treated with RGFP966 (25 mg/kg) for 12 weeks beginning at 8 weeks of age. Bar graphs shown the mean +/- S.E.M. expression value from n = 5–6 mice per group normalized to the expression of Hprt. Significant differences of p<0.05 were measured by a two-tailed, unpaired Student’s t test and are indicated by an asterisk (*).
Fig 5.
The effects of RGFP966 (25 mg/kg) on GFAP immunoreactivity in striatum of N171-82Q transgenic mice.
Immunohistochemistry experiments were performed on free-floating brain sections (25 μm) from vehicle, and RGFP966-treated N171-82Q transgenic mice using an antibody to GFAP (Abcam; 1:500 dilution). A. Representative photomicrographs showing GFAP immunoreactivity in striatum. Caudate putamen, CPu; corpus callosum, cc. Scale bar = 20 μm. B. Arrows highlight GFAP (+) cells in the caudate putamen. Scale bar = 5 μm. C. Bar graph shows significant difference between vehicle-treated and RGFP966-treated N171-82Q mice (*, P<0.05; Student’s t test, unpaired, two-tailed). Bars represent mean score ± SEM (n = 6–7 per group).