Figure 6.

(See previous page). Modulation of intracellular and extracellular SNCA in transgenic mice, by BafA1. (A) Immunohistochemistry of transgenic mice overexpressing human SNCA under the control of the PDGFB-promoter (SNCA-tg) and nontransgenic mice (non-tg) using an antibody recognizing human and mouse SNCA. Transgenic mice display SNCA⁺ inclusions in neuronal bodies and in the neuropil of the neocortex (Neoctx) compared to non-tg mice. BafA1 has been applied systemically by daily intraperitoneal injection of 0.3 mg/kg or vehicle (saline) for 5 consecutive days. The inset indicates the representative region of neocortex depicted in the 2nd and in the 3rd row. Scale bar 200 μm. Transgenic mice display SNCA immunoreactivity in the molecular layer (ML) of the hippocampus (Hippo) indicated by black arrows. Scale bar 50 μm. CA1: cornu ammonis field1; SL: stratum lacunosum (B) BafA1 treatment of SNCA-tg mice diminishes the number of neurons bearing SNCA⁺ inclusions within the neocortex compared to vehicle-treated SNCA-tg mice. (C) Quantification of the percentage of the neocortical neuropil area that shows SNCA immunoreactivity in SNCA-tg mice after BafA1 treatment. (D) Percentage of the neuropil area in the hippocampal ML that displays SNCA immunoreactivity in SNCA-tg mice after BafA1 treatment. (E) Left: Representative western blots of protein lysates probed for endogenous mouse and human SNCA depict monomeric (14 kDa) and oligomeric species (42 and 56 kDa). ACTB serves as loading control (42 kDa). Right: Western blot quantification of SNCA expression levels in BafA1-treated transgenic mice overexpressing human SNCA and normalized to ACTB (n = 3 animals per group). (F) Extracellular SNCA levels in the CSF of transgenic mice overexpressing SNCA measured by ELISA. All values are mean + s.e.m. Differences are significant at (#) P < 0.05.