Figure 7.
Antiaggregation treatment prevents UPS recovery in vivo in UbGFP:HD94 and UbGFP:R6/1 mice. A, Western blot showing detection of the UbG76V-GFP reporter in the striatum of UbGFP mice treated with vehicle (V) or riluzole (R) (first day 2 g/L and the rest at 1.2 g/L) corrected by β-actin. B, C, GFP-fluorescence detection in striatal (St, B) and cortical (Cx, C) sagittal sections from UbGFP:HD94 mice treated for 3 d with riluzole after 4 weeks of acute expression of N-mutHtt. Scale bar in B corresponds to 20 μm in B and C. D, E, G, H, J, K, Immunohistochemical detection of GFP in striatal (D, E, G, H) or cortical (J, K) sagittal sections from 3-week-old UbGFP (D, E) or UbGFP:R6/1 (G, H, J, K) mice after the 3 d vehicle (D, G, J) or riluzole (E, H, K) administration. Scale bar in D corresponds to 50 μm in panels D, E, G, H, J, and K. F, I, Histograms showing the number of GFP-positive neurons in striatal (F) or cortical (I) sagittal sections of UbGFP:R6/1 or UbGFP mice treated with vehicle or riluzole. L, Western blot showing the full-length reporter protein (UbG76V-GFP) and the truncated form (GFP), in striatum (St) or cortex (Cx) of UbGFP:R6/1 mice treated with vehicle (V) or riluzole (R); and histogram showing the densitometric quantification (in arbitrary units: a.u.) of UbG76V-GFP corrected with respect to β-actin. M, Histogram showing the chymotrypsin-like and caspase-like peptidase activities of the proteasome (by determining cleavage of the fluorogenic substrates SUC-LLVY-AMC and Z-LLE-β-NAP, respectively) assayed in striatal extracts from 3-week-old U1R6/1 mice treated with vehicle or riluzole. N–S, Confocal images of fluorescence staining with antibodies against N-mutHtt (red) and GFP (green) and with DAPI (blue) of striatal sagittal sections from 3-week-old UbGFP:R6/1 mice treated with vehicle (N–P) or riluzole (Q–S). Scale bar in N corresponds to 10 μm in N–S. Data are presented as mean ± SEM. *p < 0.05; **p < 0.005.