title: Subcellular distribution of FTY720 and FTY720-phosphate in immune cells - another aspect of Fingolimod action relevant for therapeutic application.
abstract: FTY720 (Fingolimod; Gilenya®) is an immune-modulatory prodrug which, after intracellular phosphorylation by sphingosine kinase 2 (SphK2) and export, mimics effects of the endogenous lipid mediator sphingosine-1-phosphate. Fingolimod has been introduced to treat relapsing-remitting multiple sclerosis. However, little has been published about the immune cell membrane penetration and subcellular distribution of FTY720 and FTY720-P. Thus, we applied a newly established LC-MS/MS method to analyze the subcellular distribution of FTY720 and FTY720-P in subcellular compartments of spleen cells of wild type, SphK1- and SphK2-deficient mice. These studies demonstrated that, when normalized to the original cell volume and calculated on molar basis, FTY720 and FTY720-P dramatically accumulated several hundredfold within immune cells reaching micromolar concentrations. The amount and distribution of FTY720 was differentially affected by SphK1- and SphK2-deficiency. On the background of recently described relevant intracellular FTY720 effects in the nanomolar range and the prolonged application in multiple sclerosis, this data showing a substantial intracellular accumulation of FTY720, has to be considered for benefit/risk ratio estimates.
authors.forename: Matthias
authors.initials: M
authors.lastname: Schröder
authors.forename: Olga
authors.initials: O
authors.lastname: Arlt
authors.forename: Helmut
authors.initials: H
authors.lastname: Schmidt
authors.forename: Andrea
authors.initials: A
authors.lastname: Huwiler
authors.forename: Carlo
authors.initials: C
authors.lastname: Angioni
authors.forename: Josef M
authors.initials: JM
authors.lastname: Pfeilschifter
authors.forename: Anja
authors.initials: A
authors.lastname: Schwiebs
authors.forename: Heinfried H
authors.initials: HH
authors.lastname: Radeke
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D005260:Female; D000068876:Fingolimod Hydrochloride / Q000378:metabolism* / Q000494:pharmacology*; D008246:Lysophospholipids / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D009103:Multiple Sclerosis / Q000188:drug therapy / Q000378:metabolism; D010755:Organophosphates / Q000378:metabolism* / Q000494:pharmacology*; D010766:Phosphorylation; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000172:deficiency / Q000378:metabolism; D013110:Sphingosine / Q000031:analogs & derivatives* / Q000378:metabolism / Q000494:pharmacology; D013154:Spleen / Q000166:cytology / Q000378:metabolism; D053719:Tandem Mass Spectrometry; D000099157:Sphingosine Kinase
chemical_list: D000068876:Fingolimod Hydrochloride; D008246:Lysophospholipids; D010755:Organophosphates; D017853:Phosphotransferases (Alcohol Group Acceptor); D013110:Sphingosine; D000099157:Sphingosine Kinase; C525008:FTY 720P; C060506:sphingosine 1-phosphate; C000603447:sphingosine kinase 2, mouse