title: Involvement of prostaglandin E2 in production of amyloid-beta peptides both in vitro and in vivo.
abstract: Amyloid-beta peptides (Abeta), generated by proteolysis of the beta-amyloid precursor protein (APP) by beta- and gamma-secretases, play an important role in the pathogenesis of Alzheimer disease (AD). Inflammation is also believed to be integral to the pathogenesis of AD. Here we show that prostaglandin E(2) (PGE(2)), a strong inducer of inflammation, stimulates the production of Abeta in cultured human embryonic kidney (HEK) 293 or human neuroblastoma (SH-SY5Y) cells, both of which express a mutant type of APP. We have demonstrated using subtype-specific agonists that, of the four main subtypes of PGE(2) receptors (EP(1-4)), EP(4) receptors alone or EP(2) and EP(4) receptors together are responsible for this PGE(2)-stimulated production of Abeta in HEK293 or SH-SY5Y cells, respectively. An EP(4) receptor antagonist suppressed the PGE(2)-stimulated production of Abeta in HEK293 cells. This stimulation was accompanied by an increase in cellular cAMP levels, and an analogue of cAMP stimulated the production of Abeta, demonstrating that increases in the cellular level of cAMP are responsible for the PGE(2)-stimulated production of Abeta. Immunoblotting experiments and direct measurement of gamma-secretase activity suggested that PGE(2)-stimulated production of Abeta is mediated by activation ofgamma-secretase but not of beta-secretase. Transgenic mice expressing the mutant type of APP showed lower levels of Abeta in the brain, when they were crossed with mice lacking either EP(2) or EP(4) receptors, suggesting that PGE(2)-mediated activation of EP(2) and EP(4) receptors is involved in the production of Abeta in vivo and in the pathogenesis of AD.
authors.affiliation: Graduate School of Medical and Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Kumamoto 862-0973, Japan.
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Hoshino
authors.forename: Tadashi
authors.initials: T
authors.lastname: Nakaya
authors.forename: Takashi
authors.initials: T
authors.lastname: Homan
authors.forename: Ken-ichiro
authors.initials: K
authors.lastname: Tanaka
authors.forename: Yukihiko
authors.initials: Y
authors.lastname: Sugimoto
authors.forename: Wataru
authors.initials: W
authors.lastname: Araki
authors.forename: Masami
authors.initials: M
authors.lastname: Narita
authors.forename: Shuh
authors.initials: S
authors.lastname: Narumiya
authors.forename: Toshiharu
authors.initials: T
authors.lastname: Suzuki
authors.forename: Tohru
authors.initials: T
authors.lastname: Mizushima
mesh_terms: D053829:Amyloid Precursor Protein Secretases / Q000378:metabolism; D016229:Amyloid beta-Peptides / Q000096:biosynthesis*; D000818:Animals; D002460:Cell Line; D000242:Cyclic AMP / Q000378:metabolism; D015232:Dinoprostone / Q000378:metabolism*; D004789:Enzyme Activation / Q000187:drug effects; D006801:Humans; D051379:Mice; D018345:Mice, Knockout; D010446:Peptide Fragments / Q000096:biosynthesis*; D010766:Phosphorylation; D018078:Receptors, Prostaglandin E / Q000819:agonists / Q000037:antagonists & inhibitors / Q000378:metabolism
chemical_list: D016229:Amyloid beta-Peptides; D010446:Peptide Fragments; D018078:Receptors, Prostaglandin E; D000242:Cyclic AMP; D053829:Amyloid Precursor Protein Secretases; D015232:Dinoprostone