Inhibition of Galectin-3 in a Rat Model of Epilepsy and Kainate-Activated BV2 Cells Limits Microglial Activation Through the NLRP3/Pyroptosis Pathway

Abstract

Introduction: This study aimed to investigate the possible role of galectin-3 in epilepsy and further explore its underlying mechanisms. Methods: Sprague-Dawley rats were intraperitoneally injected with 30 mg/kg pilocarpine to induce an animal model of epilepsy. To inhibit galectin-3, the epilepsy model of rats was intraperitoneally injected with TD139. The severity of the seizure was graded according to the Racine score. The pathological changes in hippocampal CA1 regions were observed by hematoxylin and eosin and Nissl staining. Enzyme-linked immunosorbent assay, quantitative real-time polymerase chain reaction, and Western blot were used to detect the levels of cytokines and pyroptosis-related factors. The in vitro effects of galectin-3 were confirmed on BV2 cells and rat primary microglia by transfection with lentivirus vectors carrying Lgals3 shRNA or by treatment with TD139. Results: A higher expression of galectin-3 was observed in the hippocampal CA1 regions of epilepsy rats than in sham rats. Inhibition of galectin-3 by administration of TD139 improved the severity of the seizure, hippocampal damage, and neuron loss. TD139 administration suppressed the expression of NLRP3, ASC, c-caspase-1, and GSDMD-N, and reduced the levels of cytokines. In kainic acid-treated microglia, Lgals3 shRNA or TD139 significantly inhibited Iba1 expression and limited NLRP3/pyroptosis-triggered inflammation. Conclusion: Galectin-3 activates the NLRP3/pyroptosis signaling pathway to promote microglial activation and neuroinflammation during epilepsy disease progression.