Central effects of fingolimod
*Corresponding author:Vítor Tedim Cruz, MD. Neurology Department. Centro Hospitalar de Entre o Douro e Vouga, EPE. Rua Dr. Cândido de Pinho. 4520-211 Santa Maria da Feira (Portugal).
E-mail: vitor.cruz@chedv.min-saude.pt
Introduction: Fingolimod, a sphingosine-1-phosphate receptor modulator, was the first oral therapy approved for relapsing-remitting multiple sclerosis, and shows a novel mechanism of action. Upon binding to S1P1 receptors in lymphocytes, the selective retention of naive and central memory T cells in secondary lymphoid tissues is promoted, preventing their egress to the central nervous system (CNS). In addition, fingolimod readily crosses the blood brain barrier, and several reports suggest a direct neuroprotective effect in the CNS.
Aim: To review the available data on the central effects of fingolimod.
Development: Imbalances between damage and repair processes are a reflection of chronic demyelination, axonal degeneration and gliosis, and seem to contribute to multiple sclerosis associated disability. Given fingolimod readily crosses the blood brain barrier, it can exert its action directly on S1P receptors present in CNS cells. Fingolimod occupies S1P receptors in oligodendrocytes, oligodendrocyte precursor cells, astrocytes, microglial cells and neurons, promoting remyelination, neuroprotection, and endogenous regeneration processes. Efficacy results from clinical trials are consistent with a mechanism of action that includes direct effects in CNS cells.
Conclusions: Current evidence suggests that the efficacy of fingolimod in the treatment of Multiple Sclerosis is due to its dual action as an immunomodulatory molecule and as a direct modulator of S1PRs in the CNS. In fact, recent reports propose that fingolimod has neuroprotective effects in several models, and open new avenues of potential therapeutic applications, such as Alzheimer's disease, cerebral malaria, neuroblastoma and neuroprotection in cranial irradiation.
Objetivo Revisar la información disponible acerca de los efectos centrales del fingolimod.
Desarrollo El desequilibrio entre los procesos lesivos y reparadores constituye un reflejo de la desmielinización crónica, la degeneración axonal y la gliosis, y parece contribuir a la discapacidad que la esclerosis múltiple acarrea. La facilidad con la que el fingolimod atraviesa la barrera hematoencefálica le permite actuar directamente sobre los receptores S1P localizados en las células del SNC. Una vez en el interior del SNC, ocupa los receptores S1P de los oligodendrocitos y de sus células precursoras, de los astrocitos, los microgliocitos y las neuronas, fomentando la remielinización, la neuroprotección y los procesos endógenos de regeneración. La eficacia evidenciada en los ensayos clínicos concuerda con un mecanismo de acción que incluiría efectos directos sobre las células del SNC.
Conclusiones Los datos disponibles indican que la eficacia del fingolimod en el tratamiento de la esclerosis múltiple se debe a su ambivalencia como molécula inmunomoduladora y moduladora directa de los receptores S1P del SNC. Tanto es así que estudios recientes le atribuyen efectos neuroprotectores en varios modelos que suscitan expectativas en torno a su posible aplicación terapéutica en la enfermedad de Alzheimer, el paludismo cerebral y el neuroblastoma, así como en la neuroprotección frente a la radioterapia craneal.