title: Gleevec increases levels of the amyloid precursor protein intracellular domain and of the amyloid-beta degrading enzyme neprilysin.
abstract: Amyloid-beta (Abeta) deposition is a major pathological hallmark of Alzheimer's disease. Gleevec, a known tyrosine kinase inhibitor, has been shown to lower Abeta secretion, and it is considered a potential basis for novel therapies for Alzheimer's disease. Here, we show that Gleevec decreases Abeta levels without the inhibition of Notch cleavage by a mechanism distinct from gamma-secretase inhibition. Gleevec does not influence gamma-secretase activity in vitro; however, treatment of cell lines leads to a dose-dependent increase in the amyloid precursor protein intracellular domain (AICD), whereas secreted Abeta is decreased. This effect is observed even in presence of a potent gamma-secretase inhibitor, suggesting that Gleevec does not activate AICD generation but instead may slow down AICD turnover. Concomitant with the increase in AICD, Gleevec leads to elevated mRNA and protein levels of the Abeta-degrading enzyme neprilysin, a potential target gene of AICD-regulated transcription. Thus, the Gleevec mediated-increase in neprilysin expression may involve enhanced AICD signaling. The finding that Gleevec elevates neprilysin levels suggests that its Abeta-lowering effect may be caused by increased Abeta-degradation.
authors.affiliation: Department of Cellular Neurology, Hertie-Institute for Clinical Brain Research, University of Tübingen, D-72076 Tübingen, Germany.
authors.forename: Yvonne S
authors.initials: YS
authors.lastname: Eisele
authors.forename: Matthias
authors.initials: M
authors.lastname: Baumann
authors.forename: Bert
authors.initials: B
authors.lastname: Klebl
authors.forename: Christina
authors.initials: C
authors.lastname: Nordhammer
authors.forename: Mathias
authors.initials: M
authors.lastname: Jucker
authors.forename: Ellen
authors.initials: E
authors.lastname: Kilger
mesh_terms: D000643:Ammonium Chloride / Q000494:pharmacology; D053829:Amyloid Precursor Protein Secretases / Q000037:antagonists & inhibitors / Q000378:metabolism; D016564:Amyloid beta-Protein Precursor / Q000737:chemistry* / Q000378:metabolism*; D001549:Benzamides; D045744:Cell Line, Tumor; D004305:Dose-Response Relationship, Drug; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D000068877:Imatinib Mesylate; D008954:Models, Biological; D015260:Neprilysin / Q000235:genetics / Q000378:metabolism*; D009419:Nerve Tissue Proteins / Q000378:metabolism; D009687:Nuclear Proteins / Q000378:metabolism; D010446:Peptide Fragments / Q000378:metabolism; D010879:Piperazines / Q000494:pharmacology*; D047428:Protein Kinase Inhibitors / Q000494:pharmacology*; D017434:Protein Structure, Tertiary; D011743:Pyrimidines / Q000494:pharmacology*; D015854:Up-Regulation / Q000187:drug effects
chemical_list: C091042:APBB1 protein, human; D016564:Amyloid beta-Protein Precursor; D001549:Benzamides; D009419:Nerve Tissue Proteins; D009687:Nuclear Proteins; D010446:Peptide Fragments; D010879:Piperazines; D047428:Protein Kinase Inhibitors; D011743:Pyrimidines; D000643:Ammonium Chloride; D000068877:Imatinib Mesylate; D053829:Amyloid Precursor Protein Secretases; D015260:Neprilysin