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FTY720/fingolimod, a sphingosine analogue, reduces amyloid-β production in neurons.

Takasugi N, Sasaki T, Ebinuma I, Osawa S, Isshiki H, Takeo K, Tomita T, Iwatsubo T - PLoS ONE (2013)

Bottom Line: Pharmacological analyses suggested that the mechanism of FTY720-mediated Aβ decrease in cells was independent of known downstream signaling pathways of S1PRs.Unexpectedly, 6-days treatment of APP transgenic mice with FTY720 resulted in a decrease in Aβ40, but an increase in Aβ42 levels in brains.These results suggest that S1PR modulators are novel type of regulators for Aβ metabolisms that are active in vitro and in vivo.

View Article: PubMed Central - PubMed

Affiliation: Department of Neuropathology and Neuroscience, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan.

ABSTRACT
Sphingosine-1-phosphate (S1P) is a pluripotent lipophilic mediator working as a ligand for G-protein coupled S1P receptors (S1PR), which is currently highlighted as a therapeutic target for autoimmune diseases including relapsing forms of multiple sclerosis. Sphingosine related compounds, FTY720 and KRP203 known as S1PR modulators, are phosphorylated by sphingosine kinase 2 (SphK2) to yield the active metabolites FTY720-P and KRP203-P, which work as functional antagonists for S1PRs. Here we report that FTY720 and KRP203 decreased production of Amyloid-β peptide (Aβ), a pathogenic proteins causative for Alzheimer disease (AD), in cultured neuronal cells. Pharmacological analyses suggested that the mechanism of FTY720-mediated Aβ decrease in cells was independent of known downstream signaling pathways of S1PRs. Unexpectedly, 6-days treatment of APP transgenic mice with FTY720 resulted in a decrease in Aβ40, but an increase in Aβ42 levels in brains. These results suggest that S1PR modulators are novel type of regulators for Aβ metabolisms that are active in vitro and in vivo.

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Related in: MedlinePlus

The effect of FTY720 on Aβ production is independent of downstream signaling of S1P receptors.(A) Levels of secreted Aβ from N2a cells co-treated with FTY720 and S1PR1 receptor antagonist W123 for 24 hrs (n = 4, mean ± SEM; *P<0.05, **P<0.01, N.S. no significant difference). (B) Levels of secreted Aβ from N2a cells co-treated with FTY720 and Gi protein inhibitor suramin for 24 hrs (n = 4, mean ± SEM; ***P<0.001, N.S. no significant difference). (C) Levels of secreted Aβ from N2a cells treated with FTY720-P for 24 hrs (n = 4, mean ± SEM). (D) In vivo effect of FTY720 on Aβ levels in AD model mice brain. Levels of soluble Aβ in the cerebral cortices of female A7 mice at 6 months of age after 6-days treatment with FTY720 (0.5 mg/kg/day, s.c.). Total brain human Aβ levels were measured by human-Aβ specific sandwich ELISA (n = 3–4, mean ± SEM, *P<0.05, ** p<0.01).
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pone-0064050-g004: The effect of FTY720 on Aβ production is independent of downstream signaling of S1P receptors.(A) Levels of secreted Aβ from N2a cells co-treated with FTY720 and S1PR1 receptor antagonist W123 for 24 hrs (n = 4, mean ± SEM; *P<0.05, **P<0.01, N.S. no significant difference). (B) Levels of secreted Aβ from N2a cells co-treated with FTY720 and Gi protein inhibitor suramin for 24 hrs (n = 4, mean ± SEM; ***P<0.001, N.S. no significant difference). (C) Levels of secreted Aβ from N2a cells treated with FTY720-P for 24 hrs (n = 4, mean ± SEM). (D) In vivo effect of FTY720 on Aβ levels in AD model mice brain. Levels of soluble Aβ in the cerebral cortices of female A7 mice at 6 months of age after 6-days treatment with FTY720 (0.5 mg/kg/day, s.c.). Total brain human Aβ levels were measured by human-Aβ specific sandwich ELISA (n = 3–4, mean ± SEM, *P<0.05, ** p<0.01).

Mentions: Phosphorylation of FTY720 by SphK takes place in the cytosol, and the resultant FTY720-P translocates to the extracellular side and acts as an agonist for S1PRs [38]. Next we examined whether known downstream signaling pathway of S1PRs was involved in the modulation of Aβ production. S1PR1, a major target of FTY720-P, is a Gi coupled receptor [39]. FTY720-P caused a significant phosphorylation of ERK1/2, a known downstream event of S1PR1-Gi signaling cascade (Fig. S2) in a similar fashion to that by SEW2871 [40]. Phosphorylation of ERK1/2 induced by SEW2871 was decreased by an authentic S1PR1 antagonist, W123 [41]. However, neither SEW2871 nor W123 affected the Aβ productions at indicated doses (Fig. S3). Then we tested co-treatment of W123 or suramin, the latter being known to work as a Gi protein inhibitor [42] together with FTY720. We found that both compounds failed to affect the decremental effect of FTY720 on Aβ production (Fig. 4A and B). In sharp contrast, extracellular addition of FTY720-P did not affect the Aβ production from N2a cells (Fig. 4C). These results raise the possibility that the molecular mechanism whereby FTY720 lowers Aβ production is independent of its antagonistic effects neither on S1PR1 nor Gi pathways and that intracellular FTY720-P lowers Aβ by an as yet identified mechanism.


FTY720/fingolimod, a sphingosine analogue, reduces amyloid-β production in neurons.

Takasugi N, Sasaki T, Ebinuma I, Osawa S, Isshiki H, Takeo K, Tomita T, Iwatsubo T - PLoS ONE (2013)

The effect of FTY720 on Aβ production is independent of downstream signaling of S1P receptors.(A) Levels of secreted Aβ from N2a cells co-treated with FTY720 and S1PR1 receptor antagonist W123 for 24 hrs (n = 4, mean ± SEM; *P<0.05, **P<0.01, N.S. no significant difference). (B) Levels of secreted Aβ from N2a cells co-treated with FTY720 and Gi protein inhibitor suramin for 24 hrs (n = 4, mean ± SEM; ***P<0.001, N.S. no significant difference). (C) Levels of secreted Aβ from N2a cells treated with FTY720-P for 24 hrs (n = 4, mean ± SEM). (D) In vivo effect of FTY720 on Aβ levels in AD model mice brain. Levels of soluble Aβ in the cerebral cortices of female A7 mice at 6 months of age after 6-days treatment with FTY720 (0.5 mg/kg/day, s.c.). Total brain human Aβ levels were measured by human-Aβ specific sandwich ELISA (n = 3–4, mean ± SEM, *P<0.05, ** p<0.01).
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Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3646787&req=5

pone-0064050-g004: The effect of FTY720 on Aβ production is independent of downstream signaling of S1P receptors.(A) Levels of secreted Aβ from N2a cells co-treated with FTY720 and S1PR1 receptor antagonist W123 for 24 hrs (n = 4, mean ± SEM; *P<0.05, **P<0.01, N.S. no significant difference). (B) Levels of secreted Aβ from N2a cells co-treated with FTY720 and Gi protein inhibitor suramin for 24 hrs (n = 4, mean ± SEM; ***P<0.001, N.S. no significant difference). (C) Levels of secreted Aβ from N2a cells treated with FTY720-P for 24 hrs (n = 4, mean ± SEM). (D) In vivo effect of FTY720 on Aβ levels in AD model mice brain. Levels of soluble Aβ in the cerebral cortices of female A7 mice at 6 months of age after 6-days treatment with FTY720 (0.5 mg/kg/day, s.c.). Total brain human Aβ levels were measured by human-Aβ specific sandwich ELISA (n = 3–4, mean ± SEM, *P<0.05, ** p<0.01).
Mentions: Phosphorylation of FTY720 by SphK takes place in the cytosol, and the resultant FTY720-P translocates to the extracellular side and acts as an agonist for S1PRs [38]. Next we examined whether known downstream signaling pathway of S1PRs was involved in the modulation of Aβ production. S1PR1, a major target of FTY720-P, is a Gi coupled receptor [39]. FTY720-P caused a significant phosphorylation of ERK1/2, a known downstream event of S1PR1-Gi signaling cascade (Fig. S2) in a similar fashion to that by SEW2871 [40]. Phosphorylation of ERK1/2 induced by SEW2871 was decreased by an authentic S1PR1 antagonist, W123 [41]. However, neither SEW2871 nor W123 affected the Aβ productions at indicated doses (Fig. S3). Then we tested co-treatment of W123 or suramin, the latter being known to work as a Gi protein inhibitor [42] together with FTY720. We found that both compounds failed to affect the decremental effect of FTY720 on Aβ production (Fig. 4A and B). In sharp contrast, extracellular addition of FTY720-P did not affect the Aβ production from N2a cells (Fig. 4C). These results raise the possibility that the molecular mechanism whereby FTY720 lowers Aβ production is independent of its antagonistic effects neither on S1PR1 nor Gi pathways and that intracellular FTY720-P lowers Aβ by an as yet identified mechanism.

Bottom Line: Pharmacological analyses suggested that the mechanism of FTY720-mediated Aβ decrease in cells was independent of known downstream signaling pathways of S1PRs.Unexpectedly, 6-days treatment of APP transgenic mice with FTY720 resulted in a decrease in Aβ40, but an increase in Aβ42 levels in brains.These results suggest that S1PR modulators are novel type of regulators for Aβ metabolisms that are active in vitro and in vivo.

View Article: PubMed Central - PubMed

Affiliation: Department of Neuropathology and Neuroscience, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan.

ABSTRACT
Sphingosine-1-phosphate (S1P) is a pluripotent lipophilic mediator working as a ligand for G-protein coupled S1P receptors (S1PR), which is currently highlighted as a therapeutic target for autoimmune diseases including relapsing forms of multiple sclerosis. Sphingosine related compounds, FTY720 and KRP203 known as S1PR modulators, are phosphorylated by sphingosine kinase 2 (SphK2) to yield the active metabolites FTY720-P and KRP203-P, which work as functional antagonists for S1PRs. Here we report that FTY720 and KRP203 decreased production of Amyloid-β peptide (Aβ), a pathogenic proteins causative for Alzheimer disease (AD), in cultured neuronal cells. Pharmacological analyses suggested that the mechanism of FTY720-mediated Aβ decrease in cells was independent of known downstream signaling pathways of S1PRs. Unexpectedly, 6-days treatment of APP transgenic mice with FTY720 resulted in a decrease in Aβ40, but an increase in Aβ42 levels in brains. These results suggest that S1PR modulators are novel type of regulators for Aβ metabolisms that are active in vitro and in vivo.

Show MeSH
Related in: MedlinePlus