Inhibition of Pannexin1 alleviates the damage of pilocarpine-induced status epilepticus through diminishing inflammatory PANoptosis-like neuron death

Abstract

Neuroinflammation has been closely associated with epileptogenesis, which is one of the contributors to neuronal cell death. PANoptosis is a newly defined form of inflammatory cell death characterized by a cascade interaction of pyroptosis, apoptosis, and necroptosis. As a large-pore channel permeable to ions and metabolites, Pannexin 1 (Panx1) is known to drive inflammatory responses and multiple programmed cell death patterns. However, the specific role of Panx1 in PANoptosis in epilepsy remains unclear. This study aims to investigate the involvement of Panx1 in inflammatory PANoptosis-like neuron death in pilocarpine-induced status epilepticus (SE) models. Elevated Panx1 levels were discovered in serum from patients with epilepsy, as well as in SE mice and pilocarpine-treated HT22 cells. Utilizing the Panx1 inhibitor probenecid improved the epileptic EEG and cognitive dysfunction in SE mice by mitigating neuron loss. The application of antagonists of pyroptosis, apoptosis, or necroptosis alone could not completely prevent cell death, while the combination of these three inhibitors provided the greatest neuroprotective effect. PANoptosome-related proteins were found to be up-regulated. Additionally, changes in morphological features, along with abnormal protein levels of several key proteins involved in pyroptosis, apoptosis, and necroptosis, indicated the occurrence of PANoptosis in vivo and in vitro. Moreover, pharmacological blockade of Panx1 ameliorated PANoptosis. These results suggest the presence of PANoptosis-like neuron death in epileptic injury. Our findings also suggest that Panx1 may be involved in PANoptosis, identifying Panx1 as a crucial regulator of the neuroinflammatory response in the context of epilepsy.