Figure 4. Autophagic clearance of α-synuclein and LC3 occurs as a delayed pathology following accumulation of insoluble Aβ42 and p62 in the brains of TgCRND8 mice.
90-day-old and 120-day-old male TgCRND8 mice or their non-transgenic littermates (nTg) were sacrificed and brains were analyzed for levels of soluble and insoluble APP metabolites, α-syn, LC3, and p62. (A, B) Composite micrograph of 90-day-old nTg (A) or TgCRND8 (B) brain immunostaining with LC3 and Aβ42 and DAPI as counter-stain (as labeled). Aβ42-immunoreactive amyloid plaques are visible in the cortex and hippocampus of TgCRND8 (B) mice, but not nTg (A) littermates. Scale bar is 1.0mm. (C) Western blot analysis of soluble and insoluble (formic acid) APP metabolites, LC3, and p62 from the gross cerebral cortex of 90- or 120-day old mice (genotype as indicated). (D-I) Analysis of Western blot integrated density following normalization to Actin of p62 (D-90-days; E-120-days), LC3 (F-90-days; G-120-days), and α-syn (H-90-days; I-120-days). Only 120-day-old TgCRND8 mice accumulated soluble LC3-I, LC3-II, p62, and α-syn by comparison to nTg littermates (C, E, G). Graphs are mean % nTg expression ± SEM; *p<0.05; **p<0.01; ***p<0.001, ****p<0.0001.