Temporal lobe epilepsy (TLE) represents a devastating neurological condition, in which approximately 4/5 of patients remain refractory for anti-convulsive drugs.
Epilepsy surgery biopsies often reveal the damage pattern of "
hippocampal sclerosis" (HS) characterized not only by neuronal loss but also pronounced
astrogliosis and inflammatory changes. Since TLE shares distinct pathogenetic aspects with
multiple sclerosis (MS), we have here scrutinized
therapeutic effects in experimental TLE of the immunmodulator
fingolimod, which is established in MS
therapy.
Fingolimod targets
sphingosine-
phosphate receptors (S1PRs). mRNAs of
fingolimod target S1PRs were augmented in two experimental post
status epilepticus (SE) TLE mouse models (suprahippocampal
kainate/
pilocarpine). SE frequently induces chronic recurrent
seizures after an extended latency referred to as epileptogenesis. Transient
fingolimod treatment of mice during epileptogenesis after suprahippocampal
kainate-induced SE revealed substantial reduction of chronic seizure activity despite lacking acute attenuation of SE itself. Intriguingly,
fingolimod exerted robust anti-convulsive activity in
kainate-induced SE mice treated in the chronic TLE stage and had neuroprotective and anti-gliotic effects and reduced cytotoxic T cell infiltrates. Finally, the expression profile of
fingolimod target-S1PRs in human hippocampal biopsy tissue of pharmacoresistant TLE patients undergoing
epilepsy surgery for seizure relief suggests repurposing of
fingolimod as novel therapeutic perspective in
focal epilepsies.