Impact of NLRP6 inflammasome on neuroinflammation in temporal lobe epilepsy

Abstract

Epilepsy is one of the most common and severe chronic brain diseases, affecting up to 70 million people worldwide. Neuroinflammation plays a central role in the progression of the disease. The Nod-Like Receptor Protein 6 (NLRP6) inflammasome assembles with apoptosis-associated speck-like protein (ASC) to cleave pro-caspase-1 into caspase-1, thus forming the NLRP6 inflammasome. This process promotes the maturation and release of downstream interleukins (IL)-18 and IL-1β, exacerbating pathological processes in various diseases. In this study, we demonstrated significantly enhanced NLRP6 expression in the cortex and hippocampus of epileptic mice, suggesting a role for the inflammasome in epilepsy. Immunofluorescence staining further revealed that NLRP6 was predominantly expressed in hippocampal neurons of these mice. Additionally, knockdown of NLRP6 reduced susceptibility to epilepsy, alleviated post-seizure neuronal damage, and decreased levels of pro-inflammatory cytokines, including IL-18, IL-1β, and IL-6. Conversely, NLRP6 overexpression produced opposite effects, which were effectively reversed by treatment with the caspase-1 inhibitor VX765. To the best of our knowledge, this is the first study to demonstrate a link between NLRP6 and the activation of the caspase-1/IL-1β/IL-18 signaling pathway in a kainic acid (KA)-induced epilepsy mouse model. Administration of VX765 alleviated pathological alterations and exerted neuroprotective effects. These findings suggest that NLRP6 plays a critical role in the initiation and progression of epilepsy.