The GR-ANXA1 pathway is a pathological player and a candidate target in epilepsy

Emma Zub, Geoffrey Canet, Rita Garbelli, Marine Blaquiere, Laura Rossini, Chiara Pastori, Madeeha Sheikh, Chris Reutelingsperger, Wendy Klement, Frederic de Bock, Etienne Audinat, Laurent Givalois, Egle Solito*, Nicola Marchi*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review


Immune changes occur in experimental and clinical epilepsy. Here, we tested the hypothesis that during epileptogenesis and spontaneous recurrent seizures (SRS) an impairment of the endogenous anti-inflammatory pathway glucocorticoid receptor (GR)-annexin A1 (ANXA1) occurs. By administrating exogenous ANXA1, we studied whether pharmacological potentiation of the anti-inflammatory response modifies seizure activity and pathophysiology. We used an in vivo model of temporal lobe epilepsy based on intrahippocampal kainic acid (KA) injection. Video-electroencephalography, molecular biology analyses on brain and peripheral blood samples, and pharmacological investigations were performed in this model. Human epileptic cortices presenting type II focal cortical dysplasia (IIa and b), hippocampi with or without hippocampal sclerosis (HS), and available controls were used to study ANXA1 expression. A decrease of phosphorylated (phospho-) GR and phospho-GR/tot-GR protein expression occurred in the hippocampus during epileptogenesis. Downstream to GR, the anti-inflammatory protein ANXA1 remained at baseline levels while inflammation installed and endured. In peripheral blood, ANXA1 and corticosterone levels showed no significant modifications during disease progression except for an early and transient increase poststatus epilepticus. These results indicate inadequate ANXA1 engagement over time and in these experimental conditions. By analyzing human brain specimens, we found that where significant inflammation exists, the pattern of ANXA1 immunoreactivity was abnormal because the typical perivascular ANXA1 immunoreactivity was reduced. We next asked whether potentiation of the endogenous anti-inflammatory mechanism by ANXA1 administration modifies the disease pathophysiology. Although with varying efficacy, administration of exogenous ANXA1 somewhat reduced the time spent in seizure activity as compared to saline. These results indicate that the anti-inflammatory GR-ANXA1 pathway is defective during experimental seizure progression. The prospect of pharmacologically restoring or potentiating this endogenous anti-inflammatory mechanism as an add-on therapeutic strategy for specific forms of epilepsy is proposed.

Original languageEnglish
Pages (from-to)13998-14009
Number of pages12
JournalFaseb Journal
Issue number12
Publication statusPublished - Dec 2019


  • annexin A1
  • glucocorticoid receptor
  • brain/peripheral inflammation
  • endogenous antiinflammatory signals
  • epilepsy
  • IL-6

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