title: Protective effect of the phosphodiesterase III inhibitor cilostazol on amyloid β-induced cognitive deficits associated with decreased amyloid β accumulation.
abstract: Alzheimer's disease (AD), which is characterized by progressive cognitive impairment, is the most common neurodegenerative disease. Here, we investigated the preventive effect of a phosphodiesterase III inhibitor, cilostazol against cognitive decline in AD mouse model. In vitro studies using N2a cells stably expressing human amyloid precursor protein Swedish mutation (N2aSwe) showed that cilostazol decreased the amyloid β (Aβ) levels in the conditioned medium and cell lysates. Cilostazol attenuated the expression of ApoE, which is responsible for Aβ aggregation, in N2aSwe. Intracerebroventricular injection of Aβ(25-35) in C57BL/6J mice resulted in increased immunoreactivity of Aβ and p-Tau, and microglia activation in the brain. Oral administration of cilostazol for 2 weeks before Aβ administration and once a day for 4 weeks post-surgery almost completely prevented the Aβ-induced increases of Aβ and p-Tau immunoreactivity, as well as CD11b immunoreactivity. However, post-treatment with cilostazol 4 weeks after Aβ administration, when Aβ was already accumulated, did not prevent the Aβ-induced neuropathological responses. Furthermore, cilostazol did not affect the neprilysin and insulin degrading enzymes involved in the degradation of the Aβ peptide, but decreased ApoE levels in Aβ-injected brain. In addition, cilostazol significantly improved spatial learning and memory in Aβ-injected mice. The findings suggest that a phosphodiesterase III inhibitor, cilostazol significantly decreased Aβ accumulation and improved memory impairment induced by Aβ(25-35). The beneficial effects of cilostazol might be explained by the reduction of Aβ accumulation and tau phosphorylation, not through an increase in Aβ degradation but via a significant decrease in ApoE-mediated Aβ aggregation. Cilostazol may be the basis of a novel strategy for the therapy of AD.
authors.affiliation: Division of Meridian and Structural Medicine, School of Korean Medicine, Pusan National University, Yangsan, Gyeongnam, Republic of Korea.
authors.forename: Sun Haeng
authors.initials: SH
authors.lastname: Park
authors.forename: Ji Hyun
authors.initials: JH
authors.lastname: Kim
authors.forename: Sun Sik
authors.initials: SS
authors.lastname: Bae
authors.forename: Ki Whan
authors.initials: KW
authors.lastname: Hong
authors.forename: Dong-Seok
authors.initials: DS
authors.lastname: Lee
authors.forename: Jae Yoon
authors.initials: JY
authors.lastname: Leem
authors.forename: Byung Tae
authors.initials: BT
authors.lastname: Choi
authors.forename: Hwa Kyoung
authors.initials: HK
authors.lastname: Shin
mesh_terms: D000544:Alzheimer Disease / Q000150:complications / Q000188:drug therapy*; D016229:Amyloid beta-Peptides / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D000818:Animals; D045744:Cell Line, Tumor; D000077407:Cilostazol; D003072:Cognition Disorders / Q000139:chemically induced / Q000188:drug therapy* / Q000209:etiology; D006801:Humans; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D010446:Peptide Fragments / Q000494:pharmacology; D058987:Phosphodiesterase 3 Inhibitors / Q000627:therapeutic use*; D010766:Phosphorylation; D013037:Spatial Behavior; D013777:Tetrazoles / Q000627:therapeutic use*; D016875:tau Proteins / Q000378:metabolism
chemical_list: D016229:Amyloid beta-Peptides; D010446:Peptide Fragments; D058987:Phosphodiesterase 3 Inhibitors; D013777:Tetrazoles; C074636:amyloid beta-protein (25-35); D016875:tau Proteins; D000077407:Cilostazol