Figure 10.

PrP 82–146 amyloid stimulates PrPC-dependent proliferation of astrocytes. A, Astrocytes prepared from cortices of 2-d-old rats were treated with the peptides (25 μm) in serum-free medium, and cell proliferation was assayed by [methyl-³H]-thymidine incorporation after 24 h. PrP 82–146wt stimulated [methyl-³H]-thymidine uptake by twofold, whereas entirely or partially scrambled peptides did not. B, C, Cell proliferation was assayed in mouse astrocytes from Prnp+/+ (B) or Prnp0/0 (C) pups as described above. PrP 82–146wt stimulated [methyl-³H]-thymidine incorporation by fourfold, whereas the partially or entirely scrambled peptides had little or no activity. Prnp0/0 astrocytes were insensitive to the proliferative stimulus of the peptides. Data are the mean ± SEM of 10–20 replicates from three to four independent experiments. *p < 0.01 versus control group by Dunnett's test.