Additional file 1: of The domestic cat as a natural animal model of Alzheimer’s disease

Figure S1. Aβ deposition in cat brains. (a) Immunohistochemistry of the cerebrum of a 17-year-old cat (case No. 20) for Aβ42 with FA pretreatment. Aβ42 aggregates are observed in the cerebral cortex but not in the hippocampus by immunohistochemistry with FA pretreatment. Higher magnification of the parietal lobe (right). Bar = 100 μm. (b) Negative control (without primary antibody) of Fig. 1c. No staining is detected in the cytoplasm. (c) ELISA for high molecular weight Aβ oligomers. Higher amounts of Aβ oligomers were seen in the brains of aged cats (15-year-old, case No. 15; 17-year-old, case No. 20) compared to the brains of young cats (3-year-old, case No. 5; 3-year-old, case No. 6). The ratio of MAP level per unit of Aβ concentration varies depending on the sizes of the Aβ oligomers. One pM of the MAP can be estimated to yield the same signal as 1.56 pM (for 20-mer) to 5.0 pM (for 100-mer) of Aβ42 oligomers [33]. Ctx, cortex; Hpc, hippocampus. Figure S2 Western blotting analysis of the SDS fraction of the cortex (Ctx) and hippocampus (Hpc) of young cats and aged cats. (a) The band corresponding to Aβ dodecamer is detected by anti-Aβ antibody 82E1. (b) Aβ oligomers that are demonstrated in Fig. 1f are not detected by anti-ApoE antibody A299. Figure S3 Expression of tau isoforms in the developing cat brain. (a) Immunohistochemistry of the hippocampus CA1 region of a fetus (case No. 1), a 2-week-old cat (case No. 3), and a 4-year-old cat (case No. 7) for 3-repeat tau (RD3), 4-repeat tau (RD4), and hyperphosphorylated tau (AT8). Only the 3-repeat tau isoform is expressed in the fetal hippocampus. The hippocampal pyramidal cells begin to express 4-repeat tau in the 2-week-old cat (arrows). Both 3-repeat and 4-repeat tau isoforms are expressed in the hippocampus of adult cat brain. Bar = 50 μm. (b) Immunohistochemistry of the cerebral cortex of a fetal cat for hyperphosphorylated tau (AT8 and AT100). The surface layer of the fetal cerebral cortex is positive for AT8 and negative for AT100. Bar = 100 μm. Table S1 Aβ protein amino acid sequences of different animal species. Table S2 Tau protein amino acid sequences of different animal species. (PDF 10834 kb)