title: Flavonoid-mediated presenilin-1 phosphorylation reduces Alzheimer's disease beta-amyloid production.
abstract: Glycogen synthase kinase 3 (GSK-3) dysregulation is implicated in the two Alzheimer's disease (AD) pathological hallmarks: beta-amyloid plaques and neurofibrillary tangles. GSK-3 inhibitors may abrogate AD pathology by inhibiting amyloidogenic gamma-secretase cleavage of amyloid precursor protein (APP). Here, we report that the citrus bioflavonoid luteolin reduces amyloid-beta (Abeta) peptide generation in both human 'Swedish' mutant APP transgene-bearing neuron-like cells and primary neurons. We also find that luteolin induces changes consistent with GSK-3 inhibition that (i) decrease amyloidogenic gamma-secretase APP processing, and (ii) promote presenilin-1 (PS1) carboxyl-terminal fragment (CTF) phosphorylation. Importantly, we find GSK-3alpha activity is essential for both PS1 CTF phosphorylation and PS1-APP interaction. As validation of these findings in vivo, we find that luteolin, when applied to the Tg2576 mouse model of AD, decreases soluble Abeta levels, reduces GSK-3 activity, and disrupts PS1-APP association. In addition, we find that Tg2576 mice treated with diosmin, a glycoside of a flavonoid structurally similar to luteolin, display significantly reduced Abeta pathology. We suggest that GSK-3 inhibition is a viable therapeutic approach for AD by impacting PS1 phosphorylation-dependent regulation of amyloidogenesis.
authors.affiliation: Department of Psychiatry & Behavioral Medicine, Rashid Laboratory for Developmental Neurobiology, Silver Child Development Center, University of South Florida, Tampa, FL 33612, USA.
authors.forename: Kavon
authors.initials: K
authors.lastname: Rezai-Zadeh
authors.forename: R
authors.initials: R
authors.lastname: Douglas Shytle
authors.forename: Yun
authors.initials: Y
authors.lastname: Bai
authors.forename: Jun
authors.initials: J
authors.lastname: Tian
authors.forename: Huayan
authors.initials: H
authors.lastname: Hou
authors.forename: Takashi
authors.initials: T
authors.lastname: Mori
authors.forename: Jin
authors.initials: J
authors.lastname: Zeng
authors.forename: Demian
authors.initials: D
authors.lastname: Obregon
authors.forename: Terrence
authors.initials: T
authors.lastname: Town
authors.forename: Jun
authors.initials: J
authors.lastname: Tan
mesh_terms: D000284:Administration, Oral; D000544:Alzheimer Disease / Q000201:enzymology / Q000378:metabolism*; D016229:Amyloid beta-Peptides / Q000096:biosynthesis*; D000818:Animals; D001921:Brain / Q000187:drug effects / Q000201:enzymology / Q000473:pathology; D002460:Cell Line; D004145:Diosmin / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects; D038362:Glycogen Synthase Kinase 3 / Q000037:antagonists & inhibitors; D000071679:Glycogen Synthase Kinase 3 beta; D006801:Humans; D047311:Luteolin / Q000737:chemistry / Q000494:pharmacology*; D051379:Mice; D008822:Mice, Transgenic; D009474:Neurons / Q000187:drug effects / Q000201:enzymology / Q000473:pathology; D010766:Phosphorylation / Q000187:drug effects; D053764:Presenilin-1 / Q000378:metabolism*; D011485:Protein Binding / Q000187:drug effects; D011499:Protein Processing, Post-Translational / Q000187:drug effects
chemical_list: D016229:Amyloid beta-Peptides; D053764:Presenilin-1; D004145:Diosmin; D000071679:Glycogen Synthase Kinase 3 beta; D038362:Glycogen Synthase Kinase 3; C448021:glycogen synthase kinase 3 alpha; D047311:Luteolin