Figure 4.

CA150 overexpression increases NA formation in the rat striatum. At 8 weeks, htt-containing aggregates were revealed by immunohistochemistry using the antibody 2B4 and nuclei stained using acridine orange. A, Number of NAs, NIs, and NA/NI ratio. The coexpression of htt171-82Q and CA150 led to a 5.65-fold increase in the number of NAs compared with rats injected with htt171-82Q alone (∗∗p < 0.001) without decreasing NIs, which corresponds to a 7.04-fold increase in the NA/NI ratio (∗∗∗p < 0.0001). The coexpression of htt171-82Q and CA150ΔQA did not modify the number of NAs or NIs compared with expression of htt171-82Q alone. Aggregate counts were performed on double-stained sections (2B4, acridine orange) for five fields of view/section at high magnification. Data are mean ± SD from six to eight animals. B, Examples of 2B4 immunostaining at 100× magnification. Top panels show 2B4 staining with gray arrowheads for NIs and blue arrowheads for NAs. Bottom panels show confocal images with 2B4 (red) and nuclear (green) staining. The NIs (white arrowheads) and NAs (yellow arrowheads) are also shown. C, Area and number of objects positive for either exogenous CA150 (HA epitope) or ubiquitin, or both, eight weeks after coinjection of htt171-82Q and CA150. D, Example of HA and ubiquitin coimmunostaining. The white arrowheads show ubiquitinated, HA-positive large objects likely to represent NIs. The blue arrowheads show ubiquitin-positive and HA-negative small objects likely to represent NAs.