title: Prophylactic versus Therapeutic Fingolimod: Restoration of Presynaptic Defects in Mice Suffering from Experimental Autoimmune Encephalomyelitis.
abstract: Fingolimod, the first oral, disease-modifying therapy for MS, has been recently proposed to modulate glutamate transmission in the central nervous system (CNS) of mice suffering from Experimental Autoimmune Encephalomyelitis (EAE) and in MS patients. Our study aims at investigating whether oral fingolimod recovers presynaptic defects that occur at different stages of disease in the CNS of EAE mice. In vivo prophylactic (0.3 mg/kg for 14 days, from the 7th day post immunization, d.p.i, the drug dissolved in the drinking water) fingolimod significantly reduced the clinical symptoms and the anxiety-related behaviour in EAE mice. Spinal cord inflammation, demyelination and glial cell activation are markers of EAE progression. These signs were ameliorated following oral fingolimod administration. Glutamate exocytosis was shown to be impaired in cortical and spinal cord terminals isolated from EAE mice at 21 ± 1 d.p.i., while GABA alteration emerged only at the spinal cord level. Prophylactic fingolimod recovered these presynaptic defects, restoring altered glutamate and GABA release efficiency. The beneficial effect occurred in a dose-dependent, region-specific manner, since lower (0.1-0.03 mg/kg) doses restored, although to a different extent, synaptic defects in cortical but not spinal cord terminals. A delayed reduction of glutamate, but not of GABA, exocytosis was observed in hippocampal terminals of EAE mice at 35 d.p.i. Therapeutic (0.3 mg/kg, from 21 d.p.i. for 14 days) fingolimod restored glutamate exocytosis in the cortex and in the hippocampus of EAE mice at 35 ± 1 d.p.i. but not in the spinal cord, where also GABAergic defects remained unmodified. These results improve our knowledge of the molecular events accounting for the beneficial effects elicited by fingolimod in demyelinating disorders.
authors.affiliation: Department of Pharmacy, Pharmacology and Toxicology Section, School of Medical and Pharmaceutical Sciences, University of Genoa, Genoa, Italy.
authors.forename: Tommaso
authors.initials: T
authors.lastname: Bonfiglio
authors.affiliation: Department of Pharmacy, Pharmacology and Toxicology Section, School of Medical and Pharmaceutical Sciences, University of Genoa, Genoa, Italy.
authors.forename: Guendalina
authors.initials: G
authors.lastname: Olivero
authors.affiliation: Department of Pharmacy, Pharmacology and Toxicology Section, School of Medical and Pharmaceutical Sciences, University of Genoa, Genoa, Italy.
authors.forename: Elisa
authors.initials: E
authors.lastname: Merega
authors.affiliation: Department of Pharmacy, Pharmacology and Toxicology Section, School of Medical and Pharmaceutical Sciences, University of Genoa, Genoa, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Di Prisco
authors.affiliation: Department of Pharmacy, Pharmacology and Toxicology Section, School of Medical and Pharmaceutical Sciences, University of Genoa, Genoa, Italy.
authors.forename: Cristina
authors.initials: C
authors.lastname: Padolecchia
authors.affiliation: Department of Pharmacy, Pharmacology and Toxicology Section, School of Medical and Pharmaceutical Sciences, University of Genoa, Genoa, Italy.|Center of Excellence for Biomedical Research, University of Genoa, Genoa, Italy.
authors.forename: Massimo
authors.initials: M
authors.lastname: Grilli
authors.affiliation: Department of Pharmacy, Pharmacology and Toxicology Section, School of Medical and Pharmaceutical Sciences, University of Genoa, Genoa, Italy.|Center of Excellence for Biomedical Research, University of Genoa, Genoa, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Milanese
authors.affiliation: Department of Neuroscience, Psychology, Drug Research and Child Health, Neurofarba, Pharmacology and Toxicology section, University of Florence, Florence, Italy.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Di Cesare Mannelli
authors.affiliation: Department of Neuroscience, Psychology, Drug Research and Child Health, Neurofarba, Pharmacology and Toxicology section, University of Florence, Florence, Italy.
authors.forename: Carla
authors.initials: C
authors.lastname: Ghelardini
authors.affiliation: Department of Pharmacy, Pharmacology and Toxicology Section, School of Medical and Pharmaceutical Sciences, University of Genoa, Genoa, Italy.|Center of Excellence for Biomedical Research, University of Genoa, Genoa, Italy.
authors.forename: Giambattista
authors.initials: G
authors.lastname: Bonanno
authors.affiliation: Department of Pharmacy, Pharmacology and Toxicology Section, School of Medical and Pharmaceutical Sciences, University of Genoa, Genoa, Italy.|Center of Excellence for Biomedical Research, University of Genoa, Genoa, Italy.
authors.forename: Mario
authors.initials: M
authors.lastname: Marchi
authors.affiliation: Department of Pharmacy, Pharmacology and Toxicology Section, School of Medical and Pharmaceutical Sciences, University of Genoa, Genoa, Italy.|Center of Excellence for Biomedical Research, University of Genoa, Genoa, Italy.
authors.forename: Anna
authors.identifier: http://orcid.org/0000-0002-4011-1165
authors.initials: A
authors.lastname: Pittaluga
mesh_terms: D000284:Administration, Oral; D000818:Animals; D002540:Cerebral Cortex / Q000187:drug effects / Q000276:immunology / Q000473:pathology; D004305:Dose-Response Relationship, Drug; D004681:Encephalomyelitis, Autoimmune, Experimental / Q000188:drug therapy* / Q000276:immunology / Q000473:pathology / Q000517:prevention & control*; D005089:Exocytosis / Q000187:drug effects; D005260:Female; D000068876:Fingolimod Hydrochloride / Q000494:pharmacology*; D018698:Glutamic Acid / Q000378:metabolism / Q000494:pharmacology; D006624:Hippocampus / Q000187:drug effects / Q000276:immunology / Q000473:pathology; D007166:Immunosuppressive Agents / Q000494:pharmacology*; D051379:Mice; D008810:Mice, Inbred C57BL; D009457:Neuroglia / Q000187:drug effects / Q000276:immunology / Q000473:pathology; D009928:Organ Specificity; D013116:Spinal Cord / Q000187:drug effects / Q000276:immunology / Q000473:pathology; D013569:Synapses / Q000187:drug effects* / Q000276:immunology / Q000473:pathology; D005680:gamma-Aminobutyric Acid / Q000378:metabolism / Q000494:pharmacology
chemical_list: D007166:Immunosuppressive Agents; D018698:Glutamic Acid; D005680:gamma-Aminobutyric Acid; D000068876:Fingolimod Hydrochloride