Three-month-old male and female mice were infused in the right OB/AON
with sonicated α-synuclein fibrils (5 μg) or an equal volume of
PBS (1 μL). Brain sections were cut in the sagittal plane after a
six-month survival period and immunostained for APE1 or NeuN. Nuclei were
labeled with Hoechst. A blinded observer analyzed APE1 expression levels and
area of select regions by tracing the area of interest in the right hemisphere
on scans captured with a 16 bit-depth, low-resolution imager (images
in
Fig. 2A). APE1 levels per unit area in
traces of the mouse (A) amygdala and (H) nucleus
accumbens. (B, I) Differential expression of APE1 protein within
the mouse amygdala and accumbens after fibril infusions. Average size of the
traced outline of the mouse (C) amygdala and (J)
accumbens in sagittal sections. (D-F) APE1 expression in the human
amygdala from the UCLA and University of Miami cohorts was determined by Western
immunoblotting and expressed as a fraction of total protein levels in
D (see
Fig. S9, S10, and
S11). (E)
Differential expression of APE1 protein in the amygdala of subjects with Lewy
body disorders compared to unaffected controls. (F) Full-length
immunoblots depicting APE1 and total protein expression. The entire lane of the
Total Protein REVERT stain was quantified. (G) Representative
images of the mouse nucleus accumbens. A blinded observer performed counts of
(K) APE1+ and (L) NeuN+
cells per field of view in the nucleus accumbens. Note that the APE1
immunostaining in the female accumbens in the PBS group is notably weaker than
in PBS-infused males, as is also evident in the quantified data, and was
captured at high exposures with low contrast to visualize virtually all signal
plus background. Data in panels A, C, D,
H, and J-L are shown as the mean ± S.D.
Two-way ANOVAs were followed by the Bonferroni post hoc in
panels A, C, H, and J-L, and
the Kruskal-Wallis was followed by the Dunn’s test in panel
D (also see parametric tests in
Fig. S11A-B). Statistical
interactions between biological sex and the disease model are noted below
respective graphs. Data in B, E, and I were analyzed
by the two-tailed Student’s t test.
*p≤0.05, **p≤0.01,
***p≤0.001 male vs. female;
+p≤0.05 PBS vs. fibrils (mice) or control vs. diseased
(humans).