title: 5-Lipoxygenase gene disruption reduces amyloid-beta pathology in a mouse model of Alzheimer's disease.
abstract: 5-Lipoxygenase (5LO), by producing leukotrienes, is a proinflammatory enzyme, and there is evidence suggesting that it is up-regulated with aging and may be involved in Alzheimer's disease (AD). In this paper, we studied the effect of 5LO-targeted gene disruption on the amyloid phenotype of a transgenic mouse model of AD, the Tg2576. Amyloid-beta (Abeta) deposition in the brains of Tg2576 mice lacking 5LO was reduced by 64-80% compared with Tg2576 controls. This reduction was associated with a similar significant decrease in Abeta levels measured by sandwich ELISA. Absence of 5LO did not induce any significant change in amyloid-beta precursor protein (APP) levels and processing, or Abeta catabolic pathways. Furthermore, in vitro studies showed that 5LO activation or 5LO metabolites increase, whereas 5LO inhibition decreases, Abeta formation, secondary to correspondent changes in gamma-secretase activity. These data establish for the first time a novel functional role for 5LO in the pathogenesis of AD-like amyloidosis, thereby modulating gamma-secretase activity. Our work suggests that pharmacological inhibition of 5LO could provide a novel therapeutic tool for AD.
authors.affiliation: Department of Pharmacology, Temple University School of Medicine, Philadelphia, PA 19140, USA.
authors.forename: Omidreza
authors.initials: O
authors.lastname: Firuzi
authors.forename: Jiamin
authors.initials: J
authors.lastname: Zhuo
authors.forename: Cinzia M
authors.initials: CM
authors.lastname: Chinnici
authors.forename: Thomas
authors.initials: T
authors.lastname: Wisniewski
authors.forename: Domenico
authors.initials: D
authors.lastname: Praticò
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000235:genetics* / Q000378:metabolism* / Q000473:pathology; D053829:Amyloid Precursor Protein Secretases / Q000378:metabolism; D016564:Amyloid beta-Protein Precursor / Q000378:metabolism*; D000818:Animals; D001094:Arachidonate 5-Lipoxygenase / Q000235:genetics*; D002478:Cells, Cultured; D004195:Disease Models, Animal; D005260:Female; D006801:Humans; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D058255:Protease Nexins; D011956:Receptors, Cell Surface / Q000378:metabolism*; D015854:Up-Regulation
chemical_list: C545487:APP protein, human; D016564:Amyloid beta-Protein Precursor; D058255:Protease Nexins; D011956:Receptors, Cell Surface; D001094:Arachidonate 5-Lipoxygenase; D053829:Amyloid Precursor Protein Secretases