Lipopolysaccharide-induced-neuroinflammation increases intracellular accumulation of amyloid precursor protein and amyloid beta peptide in APPswe transgenic mice

Neurobiol Dis. 2003 Oct;14(1):133-45. doi: 10.1016/s0969-9961(03)00069-x.


The present study was designed to examine whether brain inflammation caused by systemic administration of lipopolysaccharides (LPS) alters the expression/processing of amyloid precursor protein (APP) and increases the generation of amyloid beta peptide (Abeta). APPswe transgenic (Tg) mice were treated with either LPS or phosphate-buffered saline (PBS). In LPS-treated APPswe mice, Abeta1-40/42 was 3-fold and APP was 1.8-fold higher than those in PBS-treated mice (P < 0.05) by ELISA, Western blots and immunoprecipitation-mass spectrometry (IP-MS) ProteinChip analysis. Numbers of Abeta- and APP-immunoreactive neurons (Abeta(+) and APP(+) neurons) increased significantly in LPS-treated APPswe mice; APP(+) and Abeta(+) neurons in neocortex were associated with an increased number of F4/80-immunoreactive microglia (F4/80(+) microglia) in their anatomical environment. Our findings demonstrate that experimental neuroinflammation increases APP expression/processing and causes intracellular accumulation of Abeta. It remains to be seen whether such events can cause neuronal dysfunction/degeneration and, with time, lead to extracellular Abeta deposits, as they occur in Alzheimer's disease.

Publication types

  • Comparative Study
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Alzheimer Disease / genetics
  • Alzheimer Disease / metabolism
  • Amyloid beta-Peptides / biosynthesis
  • Amyloid beta-Peptides / genetics
  • Amyloid beta-Peptides / metabolism*
  • Amyloid beta-Protein Precursor / biosynthesis
  • Amyloid beta-Protein Precursor / genetics
  • Amyloid beta-Protein Precursor / metabolism*
  • Animals
  • Encephalitis / chemically induced
  • Encephalitis / genetics
  • Encephalitis / metabolism*
  • Intracellular Fluid / drug effects
  • Intracellular Fluid / metabolism*
  • Lipopolysaccharides / toxicity*
  • Mice
  • Mice, Inbred C3H
  • Mice, Inbred C57BL
  • Mice, Transgenic
  • Peptide Fragments / biosynthesis
  • Peptide Fragments / genetics


  • Amyloid beta-Peptides
  • Amyloid beta-Protein Precursor
  • Lipopolysaccharides
  • Peptide Fragments
  • amyloid beta-protein (1-40)
  • amyloid beta-protein (1-42)