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Advanced Neurology Early inhibition of PDK1 prevents AD-like pathology

A

B C

Figure 4. Decreased astrogliosis in Pdk1 cKO/5×FAD mice. (A) Representative images of IHC for GFAP in the cortex. Mice aged at 2.5, 4, and 6 months
were used. The immunoreactivity of GFAP was qualitatively increased in 5×FAD mice compared with the controls. The scale bar is 20 μm. (B) Enlarged
images for boxed regions in (A). The scale bar is 25 μm. (C) Quantification results showing the average number of GFAP+ cells in the cortex. There
were significant differences in the number of GFAP+ cells between 5×FAD and Pdk1 cKO/5×FAD mice at 2.5 (***P < 0.001), 4 (***P < 0.001), and 6
(***P < 0.001) months (n = 3 mice per group per age).

for pS6 Ser235/236 . Consistent with the biochemical results for APP levels were robustly higher in the 5×FAD cortex
pS6, the immunoreactivity of pS6 Ser235/236 was qualitatively than in the control cortex (Figure 6B) and significantly
reduced in Pdk1 cKO/5×FAD mice compared with 5×FAD lower in Pdk1 cKO/5×FAD mice than in 5×FAD
littermates (Figure 5C). The results are consistent with the mice (Figure 6B). Next, IHC for APP was performed.
notion that PDK1 is an upstream kinase for mTOR . The results showed that APP immunoreactivity was
[21]
3.5. Expression of APP is decreased in 5×FAD mice qualitatively reduced in Pdk1 cKO/5×FAD mice than in
with PDK1 deficiency 5×FAD mice (Figure 6C).
To determine the molecular mechanisms by which PDK1 We also performed Western blotting to examine
deletion reduces Aβ deposition, we focused on APP. the products of APP cleaved by α- and g-secretases:
Since Aβ is known to be generated from APP through Secreted (s)APPα and APP-C-terminal fragment
sequential cleavages by β- and g-secretases [52] , Western (CTF) (Figure 6D). Our results revealed that protein
blotting on APP was performed using cortical samples levels for sAPPα and APP-CTF were significantly
from four different genotypes of mice (Figure 6A). Total lower in Pdk1 cKO/5×FAD mice than in 5×FAD mice

Volume 1 Issue 3 (2022) 7 https://doi.org/10.36922/an.v1i3.153