Rodent A beta modulates the solubility and distribution of amyloid deposits in transgenic mice

J Biol Chem. 2007 Aug 3;282(31):22707-20. doi: 10.1074/jbc.M611050200. Epub 2007 Jun 7.

Abstract

The amino acid sequence of amyloid precursor protein (APP) is highly conserved, and age-related A beta aggregates have been described in a variety of vertebrate animals, with the notable exception of mice and rats. Three amino acid substitutions distinguish mouse and human A beta that might contribute to their differing properties in vivo. To examine the amyloidogenic potential of mouse A beta, we studied several lines of transgenic mice overexpressing wild-type mouse amyloid precursor protein (moAPP) either alone or in conjunction with mutant PS1 (PS1dE9). Neither overexpression of moAPP alone nor co-expression with PS1dE9 caused mice to develop Alzheimer-type amyloid pathology by 24 months of age. We further tested whether mouse A beta could accelerate the deposition of human A beta by crossing the moAPP transgenic mice to a bigenic line expressing human APPswe with PS1dE9. The triple transgenic animals (moAPP x APPswe/PS1dE9) produced 20% more A beta but formed amyloid deposits no faster and to no greater extent than APPswe/PS1dE9 siblings. Instead, the additional mouse A beta increased the detergent solubility of accumulated amyloid and exacerbated amyloid deposition in the vasculature. These findings suggest that, although mouse A beta does not influence the rate of amyloid formation, the incorporation of A beta peptides with differing sequences alters the solubility and localization of the resulting aggregates.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Amyloid / chemistry*
  • Amyloid beta-Peptides / chemistry*
  • Animals
  • Humans
  • Mice
  • Mice, Inbred C57BL
  • Mice, Transgenic
  • Molecular Sequence Data
  • Peptides / chemistry
  • Presenilin-1 / metabolism
  • Protein Structure, Tertiary
  • Sequence Homology, Amino Acid
  • Solubility
  • Transgenes

Substances

  • Amyloid
  • Amyloid beta-Peptides
  • Peptides
  • Presenilin-1