Pharmacological blockade of IL-1β/IL-1 receptor type 1 axis during epileptogenesis provides neuroprotection in two rat models of temporal lobe epilepsy

We studied whether pharmacological blockade of the IL-1 beta-mediated signaling, rapidly activated in forebrain by epileptogenic injuries, affords neuroprotection in two different rat models of status epilepticus (SE). As secondary outcome, we measured treatment's effect on SE-induced epileptogenesis. IL-1 beta signaling was blocked by systemic administration of two antiinflammatory drugs, namely human recombinant IL-1 receptor antagonist (anakinra), the naturally occurring and clinically used competitive IL-1 receptor type 1 antagonist and VX-765 a specific non-peptide inhibitor of IL-1 beta, cleavage and release. Antiinflammatory drugs were given 60 min after antiepileptic (AED) drug-controlled SE induced by pilocarpine, or 180 min after unrestrained electrical SE, for 7 days using a protocol yielding therapeutic drug levels in brain. This drug combination significantly decreased both IL-1 beta expression in astrocytes and cell loss in rat forebrain. Neuroprotection and the antiinflammatory effect were more pronounced in the electrical SE model. Onset of epilepsy, and frequency and duration of seizures 3 months after electrical SE were not significantly modified. Transcriptomic analysis in the hippocampus showed that the combined treatment did not affect the broad inflammatory response induced by SE during epileptogenesis. In particular, the treatment did not prevent the induction of the complement system and Tolllike receptors, both contributing to cell loss and seizure generation. We conclude that the IL-1 beta signaling represents an important target for reducing cell loss after SE. The data highlight a new class of clinically tested agents affording neuroprotection after a delayed post-injury intervention. Earlier blockade of this rapid onset inflammatory pathway during SE, or concomitant treatment with antiinflammatory drugs targeting additional components of the broad inflammatory response to SE, or cotreatment with AEDs, is likely to be required for optimizing beneficial outcomes. (C) 2013 Elsevier Inc. All rights reserved.