Genetic cathepsin B deficiency reduces beta-amyloid in transgenic mice expressing human wild-type amyloid precursor protein

Biochem Biophys Res Commun. 2009 Aug 21;386(2):284-8. doi: 10.1016/j.bbrc.2009.05.131. Epub 2009 Jun 6.


Neurotoxic beta-amyloid (Abeta) peptides participate in Alzheimer's disease (AD); therefore, reduction of Abeta generated from APP may provide a therapeutic approach for AD. Gene knockout studies in transgenic mice producing human Abeta may identify targets for reducing Abeta. This study shows that knockout of the cathepsin B gene in mice expressing human wild-type APP (hAPPwt) results in substantial decreases in brain Abeta40 and Abeta42 by 67% and decreases in levels of the C-terminal beta-secretase fragment (CTFbeta) derived from APP. In contrast, knockout of cathepsin B in mice expressing hAPP with the rare Swedish (Swe) and Indiana (Ind) mutations had no effect on Abeta. The difference in reduction of Abeta in hAPPwt mice, but not in hAPPSwe/Ind mice, shows that the transgenic model can affect cathepsin B gene knockout results. Since most AD patients express hAPPwt, these data validate cathepsin B as a target for development of inhibitors to lower Abeta in AD.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Alzheimer Disease / metabolism*
  • Alzheimer Disease / therapy
  • Amyloid beta-Peptides / metabolism*
  • Amyloid beta-Protein Precursor / genetics
  • Animals
  • Brain / metabolism*
  • Cathepsin B / deficiency*
  • Cathepsin B / genetics
  • Gene Knockout Techniques
  • Humans
  • Mice
  • Mice, Transgenic
  • Mutation
  • Peptide Fragments / metabolism*


  • Amyloid beta-Peptides
  • Amyloid beta-Protein Precursor
  • Peptide Fragments
  • amyloid beta-protein (1-42)
  • Cathepsin B