Figure 1.
Endophilin Deficiency Causes Age-Dependent Motor Impairments in Mice
(A) Endophilin mutant mice exhibit progressive ataxia in which onset depends on severity of endophilin deficiency. Mice were assessed on a 0–3 scale for ledge test, clasping, gait, and kyphosis from 3 to 18 months. Eight to twelve mice/genotype are shown. Average composite score for each indicated genotype at defined age was calculated; mean ± SEM (two-way ANOVA; ∗∗∗p < 0.001; ∗∗p < 0.01; ∗p < 0.05; ns > 0.05).
(B) Rotarod performance plotted as latency to fall. Motor coordination was assessed at 1–18 months. After a training session (not shown), fall latency from the accelerating rod was measured for the same genotypes as in (A). Mean ± SEM; min. eight mice/genotype; Student’s t test; ∗∗∗p < 0.001.
(C) Highest speed that endophilin mutants were able to run on DigiGait at 3 (left) and 15 (right) months. Colors represent percentage of mice able to run at indicated speed.
(D) Percentage of time both hindlimbs touch the ground simultaneously while running at 20 cm/s, quantitated for endophilin 1KO-2WT-3KO and 1KO-2HT-3WT mice in comparison to WT. Mean ± SEM, Student’s t test, ∗p<0.05, ∗∗∗p<0.001.
(E) TUNEL assay on brain sections of mice with indicated genotypes. No apoptotic signal was observed in WTs; cell death was spotted very rarely in endophilin 1KO-2WT brains and more frequently in endophilin 1,2 DKO sections (indicated by arrows). The scale bar represents 50 μm. (Right) Quantification in motor cortex (up) and hippocampus (down) is shown. Mean ± SEM; four mice/genotype.
(F) GFAP immunofluorescence in endophilin 1,2 DKO brain sections showed more gliosis compared to controls. The scale bar represents 20 μm. (Right) Quantification is shown. Mean ± SEM; four mice/genotype.
(G) Immunostaining for cleaved caspase 3 on brain slides of the indicated genotypes. Arrows indicate cells with positive caspase 3 signal. The scale bar represents 50 μm. (Right) Quantification is shown. Mean ± SEM; five mice/genotype.